/usr/bin/java -Xmx8000000000 -Xss4m -jar ./plugins/org.eclipse.equinox.launcher_1.5.800.v20200727-1323.jar -data @noDefault -ultimatedata ./data -s ../../../trunk/examples/settings/default/taipan/svcomp-Reach-32bit-Taipan_Default.epf -tc ../../../trunk/examples/toolchains/AutomizerC.xml --sifa.abstract.domain IntervalDomain -i ../sv-benchmarks/c/loops-crafted-1/theatreSquare.c -------------------------------------------------------------------------------- This is Ultimate 0.2.3-dev-f954360 [2023-03-31 23:06:47,224 INFO L177 SettingsManager]: Resetting all preferences to default values... [2023-03-31 23:06:47,225 INFO L181 SettingsManager]: Resetting UltimateCore preferences to default values [2023-03-31 23:06:47,243 INFO L184 SettingsManager]: Ultimate Commandline Interface provides no preferences, ignoring... [2023-03-31 23:06:47,243 INFO L181 SettingsManager]: Resetting Boogie Preprocessor preferences to default values [2023-03-31 23:06:47,245 INFO L181 SettingsManager]: Resetting Boogie Procedure Inliner preferences to default values [2023-03-31 23:06:47,248 INFO L181 SettingsManager]: Resetting Abstract Interpretation preferences to default values [2023-03-31 23:06:47,250 INFO L181 SettingsManager]: Resetting LassoRanker preferences to default values [2023-03-31 23:06:47,251 INFO L181 SettingsManager]: Resetting Reaching Definitions preferences to default values [2023-03-31 23:06:47,255 INFO L181 SettingsManager]: Resetting SyntaxChecker preferences to default values [2023-03-31 23:06:47,256 INFO L181 SettingsManager]: Resetting Sifa preferences to default values [2023-03-31 23:06:47,257 INFO L184 SettingsManager]: Büchi Program Product provides no preferences, ignoring... [2023-03-31 23:06:47,257 INFO L181 SettingsManager]: Resetting LTL2Aut preferences to default values [2023-03-31 23:06:47,260 INFO L181 SettingsManager]: Resetting PEA to Boogie preferences to default values [2023-03-31 23:06:47,262 INFO L181 SettingsManager]: Resetting BlockEncodingV2 preferences to default values [2023-03-31 23:06:47,263 INFO L181 SettingsManager]: Resetting ChcToBoogie preferences to default values [2023-03-31 23:06:47,263 INFO L181 SettingsManager]: Resetting AutomataScriptInterpreter preferences to default values [2023-03-31 23:06:47,264 INFO L181 SettingsManager]: Resetting BuchiAutomizer preferences to default values [2023-03-31 23:06:47,265 INFO L181 SettingsManager]: Resetting CACSL2BoogieTranslator preferences to default values [2023-03-31 23:06:47,270 INFO L181 SettingsManager]: Resetting CodeCheck preferences to default values [2023-03-31 23:06:47,271 INFO L181 SettingsManager]: Resetting InvariantSynthesis preferences to default values [2023-03-31 23:06:47,271 INFO L181 SettingsManager]: Resetting RCFGBuilder preferences to default values [2023-03-31 23:06:47,273 INFO L181 SettingsManager]: Resetting Referee preferences to default values [2023-03-31 23:06:47,274 INFO L181 SettingsManager]: Resetting TraceAbstraction preferences to default values [2023-03-31 23:06:47,280 INFO L184 SettingsManager]: TraceAbstractionConcurrent provides no preferences, ignoring... [2023-03-31 23:06:47,280 INFO L184 SettingsManager]: TraceAbstractionWithAFAs provides no preferences, ignoring... [2023-03-31 23:06:47,280 INFO L181 SettingsManager]: Resetting TreeAutomizer preferences to default values [2023-03-31 23:06:47,281 INFO L181 SettingsManager]: Resetting IcfgToChc preferences to default values [2023-03-31 23:06:47,282 INFO L181 SettingsManager]: Resetting IcfgTransformer preferences to default values [2023-03-31 23:06:47,282 INFO L184 SettingsManager]: ReqToTest provides no preferences, ignoring... [2023-03-31 23:06:47,282 INFO L181 SettingsManager]: Resetting Boogie Printer preferences to default values [2023-03-31 23:06:47,283 INFO L181 SettingsManager]: Resetting ChcSmtPrinter preferences to default values [2023-03-31 23:06:47,283 INFO L181 SettingsManager]: Resetting ReqPrinter preferences to default values [2023-03-31 23:06:47,283 INFO L181 SettingsManager]: Resetting Witness Printer preferences to default values [2023-03-31 23:06:47,284 INFO L184 SettingsManager]: Boogie PL CUP Parser provides no preferences, ignoring... [2023-03-31 23:06:47,284 INFO L181 SettingsManager]: Resetting CDTParser preferences to default values [2023-03-31 23:06:47,284 INFO L184 SettingsManager]: AutomataScriptParser provides no preferences, ignoring... [2023-03-31 23:06:47,284 INFO L184 SettingsManager]: ReqParser provides no preferences, ignoring... [2023-03-31 23:06:47,285 INFO L181 SettingsManager]: Resetting SmtParser preferences to default values [2023-03-31 23:06:47,285 INFO L181 SettingsManager]: Resetting Witness Parser preferences to default values [2023-03-31 23:06:47,285 INFO L188 SettingsManager]: Finished resetting all preferences to default values... [2023-03-31 23:06:47,287 INFO L101 SettingsManager]: Beginning loading settings from /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/../../../trunk/examples/settings/default/taipan/svcomp-Reach-32bit-Taipan_Default.epf [2023-03-31 23:06:47,311 INFO L113 SettingsManager]: Loading preferences was successful [2023-03-31 23:06:47,311 INFO L115 SettingsManager]: Preferences different from defaults after loading the file: [2023-03-31 23:06:47,312 INFO L136 SettingsManager]: Preferences of UltimateCore differ from their defaults: [2023-03-31 23:06:47,312 INFO L138 SettingsManager]: * Log level for class=de.uni_freiburg.informatik.ultimate.lib.smtlibutils.quantifier.QuantifierPusher=ERROR; [2023-03-31 23:06:47,312 INFO L136 SettingsManager]: Preferences of Boogie Procedure Inliner differ from their defaults: [2023-03-31 23:06:47,312 INFO L138 SettingsManager]: * Ignore calls to procedures called more than once=ONLY_FOR_SEQUENTIAL_PROGRAMS [2023-03-31 23:06:47,312 INFO L138 SettingsManager]: * User list type=DISABLED [2023-03-31 23:06:47,315 INFO L136 SettingsManager]: Preferences of Abstract Interpretation differ from their defaults: [2023-03-31 23:06:47,315 INFO L138 SettingsManager]: * Explicit value domain=true [2023-03-31 23:06:47,315 INFO L138 SettingsManager]: * Abstract domain for RCFG-of-the-future=PoormanAbstractDomain [2023-03-31 23:06:47,316 INFO L138 SettingsManager]: * Octagon Domain=false [2023-03-31 23:06:47,316 INFO L138 SettingsManager]: * Abstract domain=CompoundDomain [2023-03-31 23:06:47,316 INFO L138 SettingsManager]: * Check feasibility of abstract posts with an SMT solver=true [2023-03-31 23:06:47,316 INFO L138 SettingsManager]: * Use the RCFG-of-the-future interface=true [2023-03-31 23:06:47,316 INFO L138 SettingsManager]: * Interval Domain=false [2023-03-31 23:06:47,316 INFO L136 SettingsManager]: Preferences of Sifa differ from their defaults: [2023-03-31 23:06:47,316 INFO L138 SettingsManager]: * Call Summarizer=TopInputCallSummarizer [2023-03-31 23:06:47,316 INFO L138 SettingsManager]: * Simplification Technique=POLY_PAC [2023-03-31 23:06:47,317 INFO L136 SettingsManager]: Preferences of CACSL2BoogieTranslator differ from their defaults: [2023-03-31 23:06:47,317 INFO L138 SettingsManager]: * sizeof long=4 [2023-03-31 23:06:47,317 INFO L138 SettingsManager]: * Overapproximate operations on floating types=true [2023-03-31 23:06:47,317 INFO L138 SettingsManager]: * sizeof POINTER=4 [2023-03-31 23:06:47,317 INFO L138 SettingsManager]: * Check division by zero=IGNORE [2023-03-31 23:06:47,317 INFO L138 SettingsManager]: * Pointer to allocated memory at dereference=IGNORE [2023-03-31 23:06:47,317 INFO L138 SettingsManager]: * If two pointers are subtracted or compared they have the same base address=IGNORE [2023-03-31 23:06:47,318 INFO L138 SettingsManager]: * Check array bounds for arrays that are off heap=IGNORE [2023-03-31 23:06:47,318 INFO L138 SettingsManager]: * sizeof long double=12 [2023-03-31 23:06:47,318 INFO L138 SettingsManager]: * Check if freed pointer was valid=false [2023-03-31 23:06:47,318 INFO L138 SettingsManager]: * Use constant arrays=true [2023-03-31 23:06:47,318 INFO L138 SettingsManager]: * Pointer base address is valid at dereference=IGNORE [2023-03-31 23:06:47,318 INFO L136 SettingsManager]: Preferences of RCFGBuilder differ from their defaults: [2023-03-31 23:06:47,318 INFO L138 SettingsManager]: * SMT solver=External_DefaultMode [2023-03-31 23:06:47,318 INFO L138 SettingsManager]: * Command for external solver=z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in -t:2000 [2023-03-31 23:06:47,319 INFO L136 SettingsManager]: Preferences of TraceAbstraction differ from their defaults: [2023-03-31 23:06:47,319 INFO L138 SettingsManager]: * Abstract interpretation Mode=USE_PREDICATES [2023-03-31 23:06:47,319 INFO L138 SettingsManager]: * Compute Interpolants along a Counterexample=FPandBP [2023-03-31 23:06:47,319 INFO L138 SettingsManager]: * Positions where we compute the Hoare Annotation=LoopsAndPotentialCycles [2023-03-31 23:06:47,319 INFO L138 SettingsManager]: * Trace refinement strategy=SIFA_TAIPAN [2023-03-31 23:06:47,319 INFO L138 SettingsManager]: * Command for external solver=z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in [2023-03-31 23:06:47,319 INFO L138 SettingsManager]: * Compute Hoare Annotation of negated interpolant automaton, abstraction and CFG=true [2023-03-31 23:06:47,319 INFO L138 SettingsManager]: * Trace refinement exception blacklist=NONE [2023-03-31 23:06:47,319 INFO L138 SettingsManager]: * SMT solver=External_ModelsAndUnsatCoreMode WARNING: An illegal reflective access operation has occurred WARNING: Illegal reflective access by com.sun.xml.bind.v2.runtime.reflect.opt.Injector$1 (file:/storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/plugins/com.sun.xml.bind_2.2.0.v201505121915.jar) to method java.lang.ClassLoader.defineClass(java.lang.String,byte[],int,int) WARNING: Please consider reporting this to the maintainers of com.sun.xml.bind.v2.runtime.reflect.opt.Injector$1 WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations WARNING: All illegal access operations will be denied in a future release Applying setting for plugin de.uni_freiburg.informatik.ultimate.plugins.sifa: Abstract Domain -> IntervalDomain [2023-03-31 23:06:47,505 INFO L75 nceAwareModelManager]: Repository-Root is: /tmp [2023-03-31 23:06:47,518 INFO L261 ainManager$Toolchain]: [Toolchain 1]: Applicable parser(s) successfully (re)initialized [2023-03-31 23:06:47,520 INFO L217 ainManager$Toolchain]: [Toolchain 1]: Toolchain selected. [2023-03-31 23:06:47,521 INFO L271 PluginConnector]: Initializing CDTParser... [2023-03-31 23:06:47,522 INFO L275 PluginConnector]: CDTParser initialized [2023-03-31 23:06:47,523 INFO L432 ainManager$Toolchain]: [Toolchain 1]: Parsing single file: /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/../sv-benchmarks/c/loops-crafted-1/theatreSquare.c [2023-03-31 23:06:48,514 INFO L500 CDTParser]: Created temporary CDT project at NULL [2023-03-31 23:06:48,683 INFO L351 CDTParser]: Found 1 translation units. [2023-03-31 23:06:48,683 INFO L172 CDTParser]: Scanning /storage/repos/ultimate/releaseScripts/default/sv-benchmarks/c/loops-crafted-1/theatreSquare.c [2023-03-31 23:06:48,688 INFO L394 CDTParser]: About to delete temporary CDT project at /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/data/d1a4ef587/674b8c0bad514beb834e40fe48d904be/FLAG382bb4cec [2023-03-31 23:06:48,698 INFO L402 CDTParser]: Successfully deleted /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/data/d1a4ef587/674b8c0bad514beb834e40fe48d904be [2023-03-31 23:06:48,699 INFO L299 ainManager$Toolchain]: ####################### [Toolchain 1] ####################### [2023-03-31 23:06:48,700 INFO L131 ToolchainWalker]: Walking toolchain with 4 elements. [2023-03-31 23:06:48,701 INFO L113 PluginConnector]: ------------------------CACSL2BoogieTranslator---------------------------- [2023-03-31 23:06:48,701 INFO L271 PluginConnector]: Initializing CACSL2BoogieTranslator... [2023-03-31 23:06:48,703 INFO L275 PluginConnector]: CACSL2BoogieTranslator initialized [2023-03-31 23:06:48,704 INFO L185 PluginConnector]: Executing the observer ACSLObjectContainerObserver from plugin CACSL2BoogieTranslator for "CDTParser AST 31.03 11:06:48" (1/1) ... [2023-03-31 23:06:48,705 INFO L205 PluginConnector]: Invalid model from CACSL2BoogieTranslator for observer de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator.ACSLObjectContainerObserver@6bc0df37 and model type de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 31.03 11:06:48, skipping insertion in model container [2023-03-31 23:06:48,705 INFO L185 PluginConnector]: Executing the observer CACSL2BoogieTranslatorObserver from plugin CACSL2BoogieTranslator for "CDTParser AST 31.03 11:06:48" (1/1) ... [2023-03-31 23:06:48,709 INFO L145 MainTranslator]: Starting translation in SV-COMP mode [2023-03-31 23:06:48,721 INFO L178 MainTranslator]: Built tables and reachable declarations [2023-03-31 23:06:48,805 WARN L247 ndardFunctionHandler]: Function reach_error is already implemented but we override the implementation for the call at /storage/repos/ultimate/releaseScripts/default/sv-benchmarks/c/loops-crafted-1/theatreSquare.c[370,383] [2023-03-31 23:06:48,819 INFO L209 PostProcessor]: Analyzing one entry point: main [2023-03-31 23:06:48,827 INFO L203 MainTranslator]: Completed pre-run [2023-03-31 23:06:48,834 WARN L247 ndardFunctionHandler]: Function reach_error is already implemented but we override the implementation for the call at /storage/repos/ultimate/releaseScripts/default/sv-benchmarks/c/loops-crafted-1/theatreSquare.c[370,383] [2023-03-31 23:06:48,840 INFO L209 PostProcessor]: Analyzing one entry point: main [2023-03-31 23:06:48,853 INFO L208 MainTranslator]: Completed translation [2023-03-31 23:06:48,853 INFO L202 PluginConnector]: Adding new model de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 31.03 11:06:48 WrapperNode [2023-03-31 23:06:48,853 INFO L132 PluginConnector]: ------------------------ END CACSL2BoogieTranslator---------------------------- [2023-03-31 23:06:48,854 INFO L113 PluginConnector]: ------------------------Boogie Preprocessor---------------------------- [2023-03-31 23:06:48,854 INFO L271 PluginConnector]: Initializing Boogie Preprocessor... [2023-03-31 23:06:48,854 INFO L275 PluginConnector]: Boogie Preprocessor initialized [2023-03-31 23:06:48,862 INFO L185 PluginConnector]: Executing the observer EnsureBoogieModelObserver from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 31.03 11:06:48" (1/1) ... [2023-03-31 23:06:48,862 INFO L185 PluginConnector]: Executing the observer TypeChecker from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 31.03 11:06:48" (1/1) ... [2023-03-31 23:06:48,867 INFO L185 PluginConnector]: Executing the observer ConstExpander from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 31.03 11:06:48" (1/1) ... [2023-03-31 23:06:48,867 INFO L185 PluginConnector]: Executing the observer StructExpander from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 31.03 11:06:48" (1/1) ... [2023-03-31 23:06:48,870 INFO L185 PluginConnector]: Executing the observer UnstructureCode from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 31.03 11:06:48" (1/1) ... [2023-03-31 23:06:48,873 INFO L185 PluginConnector]: Executing the observer FunctionInliner from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 31.03 11:06:48" (1/1) ... [2023-03-31 23:06:48,874 INFO L185 PluginConnector]: Executing the observer LTLStepAnnotator from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 31.03 11:06:48" (1/1) ... [2023-03-31 23:06:48,874 INFO L185 PluginConnector]: Executing the observer BoogieSymbolTableConstructor from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 31.03 11:06:48" (1/1) ... [2023-03-31 23:06:48,876 INFO L132 PluginConnector]: ------------------------ END Boogie Preprocessor---------------------------- [2023-03-31 23:06:48,876 INFO L113 PluginConnector]: ------------------------RCFGBuilder---------------------------- [2023-03-31 23:06:48,876 INFO L271 PluginConnector]: Initializing RCFGBuilder... [2023-03-31 23:06:48,876 INFO L275 PluginConnector]: RCFGBuilder initialized [2023-03-31 23:06:48,877 INFO L185 PluginConnector]: Executing the observer RCFGBuilderObserver from plugin RCFGBuilder for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 31.03 11:06:48" (1/1) ... [2023-03-31 23:06:48,881 INFO L173 SolverBuilder]: Constructing external solver with command: z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in -t:2000 [2023-03-31 23:06:48,888 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:06:48,899 INFO L229 MonitoredProcess]: Starting monitored process 1 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in -t:2000 (exit command is (exit), workingDir is null) [2023-03-31 23:06:48,905 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in -t:2000 (1)] Waiting until timeout for monitored process [2023-03-31 23:06:48,929 INFO L138 BoogieDeclarations]: Found implementation of procedure ULTIMATE.init [2023-03-31 23:06:48,929 INFO L138 BoogieDeclarations]: Found implementation of procedure ULTIMATE.start [2023-03-31 23:06:48,929 INFO L138 BoogieDeclarations]: Found implementation of procedure reach_error [2023-03-31 23:06:48,930 INFO L138 BoogieDeclarations]: Found implementation of procedure __VERIFIER_assert [2023-03-31 23:06:48,930 INFO L138 BoogieDeclarations]: Found implementation of procedure correct_version [2023-03-31 23:06:48,930 INFO L138 BoogieDeclarations]: Found implementation of procedure student_version [2023-03-31 23:06:48,930 INFO L138 BoogieDeclarations]: Found implementation of procedure main [2023-03-31 23:06:48,930 INFO L130 BoogieDeclarations]: Found specification of procedure abort [2023-03-31 23:06:48,930 INFO L130 BoogieDeclarations]: Found specification of procedure __assert_fail [2023-03-31 23:06:48,930 INFO L130 BoogieDeclarations]: Found specification of procedure reach_error [2023-03-31 23:06:48,930 INFO L130 BoogieDeclarations]: Found specification of procedure #Ultimate.allocInit [2023-03-31 23:06:48,930 INFO L130 BoogieDeclarations]: Found specification of procedure __VERIFIER_nondet_int [2023-03-31 23:06:48,930 INFO L130 BoogieDeclarations]: Found specification of procedure __VERIFIER_assert [2023-03-31 23:06:48,930 INFO L130 BoogieDeclarations]: Found specification of procedure correct_version [2023-03-31 23:06:48,931 INFO L130 BoogieDeclarations]: Found specification of procedure student_version [2023-03-31 23:06:48,931 INFO L130 BoogieDeclarations]: Found specification of procedure main [2023-03-31 23:06:48,931 INFO L130 BoogieDeclarations]: Found specification of procedure ULTIMATE.init [2023-03-31 23:06:48,931 INFO L130 BoogieDeclarations]: Found specification of procedure write~init~int [2023-03-31 23:06:48,931 INFO L130 BoogieDeclarations]: Found specification of procedure ULTIMATE.start [2023-03-31 23:06:48,931 INFO L130 BoogieDeclarations]: Found specification of procedure write~int [2023-03-31 23:06:48,931 INFO L130 BoogieDeclarations]: Found specification of procedure read~int [2023-03-31 23:06:48,931 INFO L130 BoogieDeclarations]: Found specification of procedure ULTIMATE.dealloc [2023-03-31 23:06:48,989 INFO L236 CfgBuilder]: Building ICFG [2023-03-31 23:06:48,991 INFO L262 CfgBuilder]: Building CFG for each procedure with an implementation [2023-03-31 23:06:49,141 INFO L277 CfgBuilder]: Performing block encoding [2023-03-31 23:06:49,168 INFO L297 CfgBuilder]: Using the 1 location(s) as analysis (start of procedure ULTIMATE.start) [2023-03-31 23:06:49,168 INFO L302 CfgBuilder]: Removed 6 assume(true) statements. [2023-03-31 23:06:49,170 INFO L202 PluginConnector]: Adding new model de.uni_freiburg.informatik.ultimate.plugins.generator.rcfgbuilder CFG 31.03 11:06:49 BoogieIcfgContainer [2023-03-31 23:06:49,170 INFO L132 PluginConnector]: ------------------------ END RCFGBuilder---------------------------- [2023-03-31 23:06:49,172 INFO L113 PluginConnector]: ------------------------TraceAbstraction---------------------------- [2023-03-31 23:06:49,173 INFO L271 PluginConnector]: Initializing TraceAbstraction... [2023-03-31 23:06:49,176 INFO L275 PluginConnector]: TraceAbstraction initialized [2023-03-31 23:06:49,177 INFO L185 PluginConnector]: Executing the observer TraceAbstractionObserver from plugin TraceAbstraction for "CDTParser AST 31.03 11:06:48" (1/3) ... [2023-03-31 23:06:49,177 INFO L205 PluginConnector]: Invalid model from TraceAbstraction for observer de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction.TraceAbstractionObserver@33897b08 and model type de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction AST 31.03 11:06:49, skipping insertion in model container [2023-03-31 23:06:49,177 INFO L185 PluginConnector]: Executing the observer TraceAbstractionObserver from plugin TraceAbstraction for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 31.03 11:06:48" (2/3) ... [2023-03-31 23:06:49,177 INFO L205 PluginConnector]: Invalid model from TraceAbstraction for observer de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction.TraceAbstractionObserver@33897b08 and model type de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction AST 31.03 11:06:49, skipping insertion in model container [2023-03-31 23:06:49,178 INFO L185 PluginConnector]: Executing the observer TraceAbstractionObserver from plugin TraceAbstraction for "de.uni_freiburg.informatik.ultimate.plugins.generator.rcfgbuilder CFG 31.03 11:06:49" (3/3) ... [2023-03-31 23:06:49,184 INFO L112 eAbstractionObserver]: Analyzing ICFG theatreSquare.c [2023-03-31 23:06:49,195 INFO L203 ceAbstractionStarter]: Automizer settings: Hoare:true NWA Interpolation:FPandBP Determinization: PREDICATE_ABSTRACTION [2023-03-31 23:06:49,196 INFO L162 ceAbstractionStarter]: Applying trace abstraction to program that has 1 error locations. [2023-03-31 23:06:49,244 INFO L356 AbstractCegarLoop]: ======== Iteration 0 == of CEGAR loop == AllErrorsAtOnce ======== [2023-03-31 23:06:49,250 INFO L357 AbstractCegarLoop]: Settings: SEPARATE_VIOLATION_CHECK=true, mInterprocedural=true, mMaxIterations=1000000, mWatchIteration=1000000, mArtifact=RCFG, mInterpolation=FPandBP, mInterpolantAutomaton=STRAIGHT_LINE, mDumpAutomata=false, mAutomataFormat=ATS_NUMERATE, mDumpPath=., mDeterminiation=PREDICATE_ABSTRACTION, mMinimize=MINIMIZE_SEVPA, mHoare=true, mAutomataTypeConcurrency=FINITE_AUTOMATA, mHoareTripleChecks=INCREMENTAL, mHoareAnnotationPositions=LoopsAndPotentialCycles, mDumpOnlyReuseAutomata=false, mLimitTraceHistogram=0, mErrorLocTimeLimit=0, mLimitPathProgramCount=0, mCollectInterpolantStatistics=true, mHeuristicEmptinessCheck=false, mHeuristicEmptinessCheckAStarHeuristic=ZERO, mHeuristicEmptinessCheckAStarHeuristicRandomSeed=1337, mHeuristicEmptinessCheckSmtFeatureScoringMethod=DAGSIZE, mSMTFeatureExtraction=false, mSMTFeatureExtractionDumpPath=., mOverrideInterpolantAutomaton=false, mMcrInterpolantMethod=WP, mPorIndependenceSettings=[Lde.uni_freiburg.informatik.ultimate.lib.tracecheckerutils.partialorder.independence.IndependenceSettings;@14295807, mLbeIndependenceSettings=[IndependenceType=SEMANTIC, AbstractionType=NONE, UseConditional=false, UseSemiCommutativity=true, Solver=Z3, SolverTimeout=1000ms] [2023-03-31 23:06:49,250 INFO L358 AbstractCegarLoop]: Starting to check reachability of 1 error locations. [2023-03-31 23:06:49,253 INFO L276 IsEmpty]: Start isEmpty. Operand has 31 states, 19 states have (on average 1.4736842105263157) internal successors, (28), 20 states have internal predecessors, (28), 5 states have call successors, (5), 5 states have call predecessors, (5), 5 states have return successors, (5), 5 states have call predecessors, (5), 5 states have call successors, (5) [2023-03-31 23:06:49,257 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 11 [2023-03-31 23:06:49,257 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:06:49,258 INFO L195 NwaCegarLoop]: trace histogram [1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:06:49,258 INFO L420 AbstractCegarLoop]: === Iteration 1 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:06:49,261 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:06:49,261 INFO L85 PathProgramCache]: Analyzing trace with hash -1476216955, now seen corresponding path program 1 times [2023-03-31 23:06:49,267 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:06:49,267 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [864949221] [2023-03-31 23:06:49,268 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:06:49,268 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:06:49,345 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:06:49,470 INFO L134 CoverageAnalysis]: Checked inductivity of 0 backedges. 0 proven. 0 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2023-03-31 23:06:49,471 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:06:49,471 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [864949221] [2023-03-31 23:06:49,471 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [864949221] provided 1 perfect and 0 imperfect interpolant sequences [2023-03-31 23:06:49,472 INFO L185 FreeRefinementEngine]: Found 1 perfect and 0 imperfect interpolant sequences. [2023-03-31 23:06:49,472 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [5] imperfect sequences [] total 5 [2023-03-31 23:06:49,473 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [84227199] [2023-03-31 23:06:49,473 INFO L85 oduleStraightlineAll]: Using 1 perfect interpolants to construct interpolant automaton [2023-03-31 23:06:49,476 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 5 states [2023-03-31 23:06:49,476 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:06:49,499 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 5 interpolants. [2023-03-31 23:06:49,501 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=7, Invalid=13, Unknown=0, NotChecked=0, Total=20 [2023-03-31 23:06:49,503 INFO L87 Difference]: Start difference. First operand has 31 states, 19 states have (on average 1.4736842105263157) internal successors, (28), 20 states have internal predecessors, (28), 5 states have call successors, (5), 5 states have call predecessors, (5), 5 states have return successors, (5), 5 states have call predecessors, (5), 5 states have call successors, (5) Second operand has 5 states, 5 states have (on average 1.2) internal successors, (6), 4 states have internal predecessors, (6), 2 states have call successors, (3), 2 states have call predecessors, (3), 1 states have return successors, (1), 1 states have call predecessors, (1), 1 states have call successors, (1) [2023-03-31 23:06:49,558 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:06:49,559 INFO L93 Difference]: Finished difference Result 46 states and 54 transitions. [2023-03-31 23:06:49,560 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 6 states. [2023-03-31 23:06:49,560 INFO L78 Accepts]: Start accepts. Automaton has has 5 states, 5 states have (on average 1.2) internal successors, (6), 4 states have internal predecessors, (6), 2 states have call successors, (3), 2 states have call predecessors, (3), 1 states have return successors, (1), 1 states have call predecessors, (1), 1 states have call successors, (1) Word has length 10 [2023-03-31 23:06:49,561 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:06:49,564 INFO L225 Difference]: With dead ends: 46 [2023-03-31 23:06:49,564 INFO L226 Difference]: Without dead ends: 25 [2023-03-31 23:06:49,566 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 6 GetRequests, 2 SyntacticMatches, 0 SemanticMatches, 4 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 0 ImplicationChecksByTransitivity, 0.0s TimeCoverageRelationStatistics Valid=11, Invalid=19, Unknown=0, NotChecked=0, Total=30 [2023-03-31 23:06:49,568 INFO L413 NwaCegarLoop]: 26 mSDtfsCounter, 8 mSDsluCounter, 69 mSDsCounter, 0 mSdLazyCounter, 47 mSolverCounterSat, 1 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.0s Time, 0 mProtectedPredicate, 0 mProtectedAction, 10 SdHoareTripleChecker+Valid, 95 SdHoareTripleChecker+Invalid, 48 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 1 IncrementalHoareTripleChecker+Valid, 47 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.0s IncrementalHoareTripleChecker+Time [2023-03-31 23:06:49,569 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [10 Valid, 95 Invalid, 48 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [1 Valid, 47 Invalid, 0 Unknown, 0 Unchecked, 0.0s Time] [2023-03-31 23:06:49,579 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 25 states. [2023-03-31 23:06:49,587 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 25 to 25. [2023-03-31 23:06:49,588 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 25 states, 16 states have (on average 1.375) internal successors, (22), 16 states have internal predecessors, (22), 5 states have call successors, (5), 5 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 3 states have call successors, (3) [2023-03-31 23:06:49,589 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 25 states to 25 states and 30 transitions. [2023-03-31 23:06:49,590 INFO L78 Accepts]: Start accepts. Automaton has 25 states and 30 transitions. Word has length 10 [2023-03-31 23:06:49,590 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:06:49,590 INFO L495 AbstractCegarLoop]: Abstraction has 25 states and 30 transitions. [2023-03-31 23:06:49,590 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 5 states, 5 states have (on average 1.2) internal successors, (6), 4 states have internal predecessors, (6), 2 states have call successors, (3), 2 states have call predecessors, (3), 1 states have return successors, (1), 1 states have call predecessors, (1), 1 states have call successors, (1) [2023-03-31 23:06:49,591 INFO L276 IsEmpty]: Start isEmpty. Operand 25 states and 30 transitions. [2023-03-31 23:06:49,591 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 25 [2023-03-31 23:06:49,591 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:06:49,591 INFO L195 NwaCegarLoop]: trace histogram [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:06:49,592 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable0 [2023-03-31 23:06:49,592 INFO L420 AbstractCegarLoop]: === Iteration 2 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:06:49,592 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:06:49,592 INFO L85 PathProgramCache]: Analyzing trace with hash 1318282951, now seen corresponding path program 1 times [2023-03-31 23:06:49,593 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:06:49,593 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [988570862] [2023-03-31 23:06:49,593 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:06:49,593 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:06:49,610 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:06:49,866 INFO L134 CoverageAnalysis]: Checked inductivity of 0 backedges. 0 proven. 0 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2023-03-31 23:06:49,866 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:06:49,867 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [988570862] [2023-03-31 23:06:49,867 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [988570862] provided 1 perfect and 0 imperfect interpolant sequences [2023-03-31 23:06:49,867 INFO L185 FreeRefinementEngine]: Found 1 perfect and 0 imperfect interpolant sequences. [2023-03-31 23:06:49,867 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [12] imperfect sequences [] total 12 [2023-03-31 23:06:49,867 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [999405059] [2023-03-31 23:06:49,867 INFO L85 oduleStraightlineAll]: Using 1 perfect interpolants to construct interpolant automaton [2023-03-31 23:06:49,868 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 12 states [2023-03-31 23:06:49,868 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:06:49,870 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 12 interpolants. [2023-03-31 23:06:49,871 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=21, Invalid=111, Unknown=0, NotChecked=0, Total=132 [2023-03-31 23:06:49,871 INFO L87 Difference]: Start difference. First operand 25 states and 30 transitions. Second operand has 12 states, 8 states have (on average 2.0) internal successors, (16), 9 states have internal predecessors, (16), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:06:50,024 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:06:50,025 INFO L93 Difference]: Finished difference Result 39 states and 47 transitions. [2023-03-31 23:06:50,025 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 13 states. [2023-03-31 23:06:50,025 INFO L78 Accepts]: Start accepts. Automaton has has 12 states, 8 states have (on average 2.0) internal successors, (16), 9 states have internal predecessors, (16), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) Word has length 24 [2023-03-31 23:06:50,026 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:06:50,029 INFO L225 Difference]: With dead ends: 39 [2023-03-31 23:06:50,030 INFO L226 Difference]: Without dead ends: 33 [2023-03-31 23:06:50,030 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 18 GetRequests, 2 SyntacticMatches, 0 SemanticMatches, 16 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 15 ImplicationChecksByTransitivity, 0.1s TimeCoverageRelationStatistics Valid=45, Invalid=261, Unknown=0, NotChecked=0, Total=306 [2023-03-31 23:06:50,031 INFO L413 NwaCegarLoop]: 18 mSDtfsCounter, 6 mSDsluCounter, 159 mSDsCounter, 0 mSdLazyCounter, 149 mSolverCounterSat, 1 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.1s Time, 0 mProtectedPredicate, 0 mProtectedAction, 10 SdHoareTripleChecker+Valid, 177 SdHoareTripleChecker+Invalid, 150 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 1 IncrementalHoareTripleChecker+Valid, 149 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.1s IncrementalHoareTripleChecker+Time [2023-03-31 23:06:50,031 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [10 Valid, 177 Invalid, 150 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [1 Valid, 149 Invalid, 0 Unknown, 0 Unchecked, 0.1s Time] [2023-03-31 23:06:50,032 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 33 states. [2023-03-31 23:06:50,039 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 33 to 31. [2023-03-31 23:06:50,039 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 31 states, 19 states have (on average 1.4210526315789473) internal successors, (27), 21 states have internal predecessors, (27), 6 states have call successors, (6), 5 states have call predecessors, (6), 5 states have return successors, (6), 4 states have call predecessors, (6), 4 states have call successors, (6) [2023-03-31 23:06:50,040 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 31 states to 31 states and 39 transitions. [2023-03-31 23:06:50,040 INFO L78 Accepts]: Start accepts. Automaton has 31 states and 39 transitions. Word has length 24 [2023-03-31 23:06:50,040 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:06:50,040 INFO L495 AbstractCegarLoop]: Abstraction has 31 states and 39 transitions. [2023-03-31 23:06:50,041 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 12 states, 8 states have (on average 2.0) internal successors, (16), 9 states have internal predecessors, (16), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:06:50,041 INFO L276 IsEmpty]: Start isEmpty. Operand 31 states and 39 transitions. [2023-03-31 23:06:50,042 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 26 [2023-03-31 23:06:50,042 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:06:50,042 INFO L195 NwaCegarLoop]: trace histogram [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:06:50,042 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable1 [2023-03-31 23:06:50,042 INFO L420 AbstractCegarLoop]: === Iteration 3 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:06:50,043 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:06:50,043 INFO L85 PathProgramCache]: Analyzing trace with hash 862814945, now seen corresponding path program 1 times [2023-03-31 23:06:50,043 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:06:50,043 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [180821358] [2023-03-31 23:06:50,043 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:06:50,043 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:06:50,060 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:06:50,098 INFO L134 CoverageAnalysis]: Checked inductivity of 1 backedges. 1 proven. 0 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2023-03-31 23:06:50,099 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:06:50,099 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [180821358] [2023-03-31 23:06:50,099 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [180821358] provided 1 perfect and 0 imperfect interpolant sequences [2023-03-31 23:06:50,099 INFO L185 FreeRefinementEngine]: Found 1 perfect and 0 imperfect interpolant sequences. [2023-03-31 23:06:50,099 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [4] imperfect sequences [] total 4 [2023-03-31 23:06:50,099 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [169393487] [2023-03-31 23:06:50,099 INFO L85 oduleStraightlineAll]: Using 1 perfect interpolants to construct interpolant automaton [2023-03-31 23:06:50,100 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 4 states [2023-03-31 23:06:50,100 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:06:50,100 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 4 interpolants. [2023-03-31 23:06:50,100 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=6, Invalid=6, Unknown=0, NotChecked=0, Total=12 [2023-03-31 23:06:50,101 INFO L87 Difference]: Start difference. First operand 31 states and 39 transitions. Second operand has 4 states, 4 states have (on average 4.25) internal successors, (17), 4 states have internal predecessors, (17), 2 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 2 states have call predecessors, (3), 1 states have call successors, (3) [2023-03-31 23:06:50,120 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:06:50,120 INFO L93 Difference]: Finished difference Result 43 states and 55 transitions. [2023-03-31 23:06:50,121 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 4 states. [2023-03-31 23:06:50,121 INFO L78 Accepts]: Start accepts. Automaton has has 4 states, 4 states have (on average 4.25) internal successors, (17), 4 states have internal predecessors, (17), 2 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 2 states have call predecessors, (3), 1 states have call successors, (3) Word has length 25 [2023-03-31 23:06:50,121 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:06:50,122 INFO L225 Difference]: With dead ends: 43 [2023-03-31 23:06:50,122 INFO L226 Difference]: Without dead ends: 35 [2023-03-31 23:06:50,125 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 5 GetRequests, 3 SyntacticMatches, 0 SemanticMatches, 2 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 0 ImplicationChecksByTransitivity, 0.0s TimeCoverageRelationStatistics Valid=6, Invalid=6, Unknown=0, NotChecked=0, Total=12 [2023-03-31 23:06:50,126 INFO L413 NwaCegarLoop]: 23 mSDtfsCounter, 3 mSDsluCounter, 22 mSDsCounter, 0 mSdLazyCounter, 19 mSolverCounterSat, 0 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.0s Time, 0 mProtectedPredicate, 0 mProtectedAction, 3 SdHoareTripleChecker+Valid, 45 SdHoareTripleChecker+Invalid, 19 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 0 IncrementalHoareTripleChecker+Valid, 19 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.0s IncrementalHoareTripleChecker+Time [2023-03-31 23:06:50,126 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [3 Valid, 45 Invalid, 19 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [0 Valid, 19 Invalid, 0 Unknown, 0 Unchecked, 0.0s Time] [2023-03-31 23:06:50,127 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 35 states. [2023-03-31 23:06:50,132 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 35 to 34. [2023-03-31 23:06:50,132 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 34 states, 22 states have (on average 1.4545454545454546) internal successors, (32), 24 states have internal predecessors, (32), 6 states have call successors, (6), 5 states have call predecessors, (6), 5 states have return successors, (6), 4 states have call predecessors, (6), 4 states have call successors, (6) [2023-03-31 23:06:50,133 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 34 states to 34 states and 44 transitions. [2023-03-31 23:06:50,133 INFO L78 Accepts]: Start accepts. Automaton has 34 states and 44 transitions. Word has length 25 [2023-03-31 23:06:50,133 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:06:50,133 INFO L495 AbstractCegarLoop]: Abstraction has 34 states and 44 transitions. [2023-03-31 23:06:50,133 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 4 states, 4 states have (on average 4.25) internal successors, (17), 4 states have internal predecessors, (17), 2 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 2 states have call predecessors, (3), 1 states have call successors, (3) [2023-03-31 23:06:50,133 INFO L276 IsEmpty]: Start isEmpty. Operand 34 states and 44 transitions. [2023-03-31 23:06:50,134 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 26 [2023-03-31 23:06:50,134 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:06:50,134 INFO L195 NwaCegarLoop]: trace histogram [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:06:50,134 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable2 [2023-03-31 23:06:50,134 INFO L420 AbstractCegarLoop]: === Iteration 4 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:06:50,135 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:06:50,135 INFO L85 PathProgramCache]: Analyzing trace with hash 1891323942, now seen corresponding path program 1 times [2023-03-31 23:06:50,135 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:06:50,135 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [777647529] [2023-03-31 23:06:50,135 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:06:50,135 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:06:50,144 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:06:50,180 INFO L134 CoverageAnalysis]: Checked inductivity of 1 backedges. 1 proven. 0 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2023-03-31 23:06:50,181 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:06:50,181 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [777647529] [2023-03-31 23:06:50,181 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [777647529] provided 1 perfect and 0 imperfect interpolant sequences [2023-03-31 23:06:50,181 INFO L185 FreeRefinementEngine]: Found 1 perfect and 0 imperfect interpolant sequences. [2023-03-31 23:06:50,181 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [4] imperfect sequences [] total 4 [2023-03-31 23:06:50,181 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [953124356] [2023-03-31 23:06:50,181 INFO L85 oduleStraightlineAll]: Using 1 perfect interpolants to construct interpolant automaton [2023-03-31 23:06:50,182 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 4 states [2023-03-31 23:06:50,182 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:06:50,182 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 4 interpolants. [2023-03-31 23:06:50,182 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=6, Invalid=6, Unknown=0, NotChecked=0, Total=12 [2023-03-31 23:06:50,183 INFO L87 Difference]: Start difference. First operand 34 states and 44 transitions. Second operand has 4 states, 4 states have (on average 4.25) internal successors, (17), 4 states have internal predecessors, (17), 2 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 2 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:06:50,198 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:06:50,198 INFO L93 Difference]: Finished difference Result 58 states and 77 transitions. [2023-03-31 23:06:50,198 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 4 states. [2023-03-31 23:06:50,199 INFO L78 Accepts]: Start accepts. Automaton has has 4 states, 4 states have (on average 4.25) internal successors, (17), 4 states have internal predecessors, (17), 2 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 2 states have call predecessors, (3), 2 states have call successors, (3) Word has length 25 [2023-03-31 23:06:50,199 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:06:50,199 INFO L225 Difference]: With dead ends: 58 [2023-03-31 23:06:50,199 INFO L226 Difference]: Without dead ends: 38 [2023-03-31 23:06:50,200 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 5 GetRequests, 3 SyntacticMatches, 0 SemanticMatches, 2 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 0 ImplicationChecksByTransitivity, 0.0s TimeCoverageRelationStatistics Valid=6, Invalid=6, Unknown=0, NotChecked=0, Total=12 [2023-03-31 23:06:50,200 INFO L413 NwaCegarLoop]: 22 mSDtfsCounter, 3 mSDsluCounter, 21 mSDsCounter, 0 mSdLazyCounter, 19 mSolverCounterSat, 0 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.0s Time, 0 mProtectedPredicate, 0 mProtectedAction, 3 SdHoareTripleChecker+Valid, 43 SdHoareTripleChecker+Invalid, 19 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 0 IncrementalHoareTripleChecker+Valid, 19 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.0s IncrementalHoareTripleChecker+Time [2023-03-31 23:06:50,201 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [3 Valid, 43 Invalid, 19 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [0 Valid, 19 Invalid, 0 Unknown, 0 Unchecked, 0.0s Time] [2023-03-31 23:06:50,201 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 38 states. [2023-03-31 23:06:50,205 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 38 to 37. [2023-03-31 23:06:50,206 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 37 states, 25 states have (on average 1.48) internal successors, (37), 27 states have internal predecessors, (37), 6 states have call successors, (6), 5 states have call predecessors, (6), 5 states have return successors, (6), 4 states have call predecessors, (6), 4 states have call successors, (6) [2023-03-31 23:06:50,206 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 37 states to 37 states and 49 transitions. [2023-03-31 23:06:50,206 INFO L78 Accepts]: Start accepts. Automaton has 37 states and 49 transitions. Word has length 25 [2023-03-31 23:06:50,207 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:06:50,207 INFO L495 AbstractCegarLoop]: Abstraction has 37 states and 49 transitions. [2023-03-31 23:06:50,207 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 4 states, 4 states have (on average 4.25) internal successors, (17), 4 states have internal predecessors, (17), 2 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 2 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:06:50,207 INFO L276 IsEmpty]: Start isEmpty. Operand 37 states and 49 transitions. [2023-03-31 23:06:50,208 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 27 [2023-03-31 23:06:50,208 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:06:50,208 INFO L195 NwaCegarLoop]: trace histogram [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:06:50,208 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable3 [2023-03-31 23:06:50,208 INFO L420 AbstractCegarLoop]: === Iteration 5 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:06:50,208 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:06:50,209 INFO L85 PathProgramCache]: Analyzing trace with hash -90029159, now seen corresponding path program 1 times [2023-03-31 23:06:50,209 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:06:50,209 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1892418925] [2023-03-31 23:06:50,209 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:06:50,209 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:06:50,226 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:06:50,282 INFO L134 CoverageAnalysis]: Checked inductivity of 2 backedges. 0 proven. 0 refuted. 0 times theorem prover too weak. 2 trivial. 0 not checked. [2023-03-31 23:06:50,282 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:06:50,282 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1892418925] [2023-03-31 23:06:50,282 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1892418925] provided 1 perfect and 0 imperfect interpolant sequences [2023-03-31 23:06:50,282 INFO L185 FreeRefinementEngine]: Found 1 perfect and 0 imperfect interpolant sequences. [2023-03-31 23:06:50,283 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [5] imperfect sequences [] total 5 [2023-03-31 23:06:50,283 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1433163314] [2023-03-31 23:06:50,284 INFO L85 oduleStraightlineAll]: Using 1 perfect interpolants to construct interpolant automaton [2023-03-31 23:06:50,284 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 5 states [2023-03-31 23:06:50,284 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:06:50,284 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 5 interpolants. [2023-03-31 23:06:50,285 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=7, Invalid=13, Unknown=0, NotChecked=0, Total=20 [2023-03-31 23:06:50,285 INFO L87 Difference]: Start difference. First operand 37 states and 49 transitions. Second operand has 5 states, 4 states have (on average 4.5) internal successors, (18), 5 states have internal predecessors, (18), 3 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 2 states have call predecessors, (3), 3 states have call successors, (3) [2023-03-31 23:06:50,332 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:06:50,333 INFO L93 Difference]: Finished difference Result 56 states and 72 transitions. [2023-03-31 23:06:50,333 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 5 states. [2023-03-31 23:06:50,333 INFO L78 Accepts]: Start accepts. Automaton has has 5 states, 4 states have (on average 4.5) internal successors, (18), 5 states have internal predecessors, (18), 3 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 2 states have call predecessors, (3), 3 states have call successors, (3) Word has length 26 [2023-03-31 23:06:50,334 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:06:50,336 INFO L225 Difference]: With dead ends: 56 [2023-03-31 23:06:50,337 INFO L226 Difference]: Without dead ends: 35 [2023-03-31 23:06:50,337 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 6 GetRequests, 2 SyntacticMatches, 0 SemanticMatches, 4 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 0 ImplicationChecksByTransitivity, 0.0s TimeCoverageRelationStatistics Valid=11, Invalid=19, Unknown=0, NotChecked=0, Total=30 [2023-03-31 23:06:50,337 INFO L413 NwaCegarLoop]: 22 mSDtfsCounter, 7 mSDsluCounter, 52 mSDsCounter, 0 mSdLazyCounter, 40 mSolverCounterSat, 0 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.0s Time, 0 mProtectedPredicate, 0 mProtectedAction, 9 SdHoareTripleChecker+Valid, 74 SdHoareTripleChecker+Invalid, 40 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 0 IncrementalHoareTripleChecker+Valid, 40 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.0s IncrementalHoareTripleChecker+Time [2023-03-31 23:06:50,338 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [9 Valid, 74 Invalid, 40 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [0 Valid, 40 Invalid, 0 Unknown, 0 Unchecked, 0.0s Time] [2023-03-31 23:06:50,338 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 35 states. [2023-03-31 23:06:50,341 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 35 to 35. [2023-03-31 23:06:50,341 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 35 states, 23 states have (on average 1.434782608695652) internal successors, (33), 25 states have internal predecessors, (33), 6 states have call successors, (6), 5 states have call predecessors, (6), 5 states have return successors, (6), 4 states have call predecessors, (6), 4 states have call successors, (6) [2023-03-31 23:06:50,342 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 35 states to 35 states and 45 transitions. [2023-03-31 23:06:50,342 INFO L78 Accepts]: Start accepts. Automaton has 35 states and 45 transitions. Word has length 26 [2023-03-31 23:06:50,342 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:06:50,342 INFO L495 AbstractCegarLoop]: Abstraction has 35 states and 45 transitions. [2023-03-31 23:06:50,342 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 5 states, 4 states have (on average 4.5) internal successors, (18), 5 states have internal predecessors, (18), 3 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 2 states have call predecessors, (3), 3 states have call successors, (3) [2023-03-31 23:06:50,342 INFO L276 IsEmpty]: Start isEmpty. Operand 35 states and 45 transitions. [2023-03-31 23:06:50,343 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 27 [2023-03-31 23:06:50,344 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:06:50,344 INFO L195 NwaCegarLoop]: trace histogram [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:06:50,344 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable4 [2023-03-31 23:06:50,344 INFO L420 AbstractCegarLoop]: === Iteration 6 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:06:50,344 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:06:50,344 INFO L85 PathProgramCache]: Analyzing trace with hash 179424187, now seen corresponding path program 1 times [2023-03-31 23:06:50,344 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:06:50,345 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1784149891] [2023-03-31 23:06:50,345 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:06:50,345 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:06:50,353 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:06:50,399 INFO L134 CoverageAnalysis]: Checked inductivity of 2 backedges. 0 proven. 0 refuted. 0 times theorem prover too weak. 2 trivial. 0 not checked. [2023-03-31 23:06:50,400 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:06:50,400 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1784149891] [2023-03-31 23:06:50,400 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1784149891] provided 1 perfect and 0 imperfect interpolant sequences [2023-03-31 23:06:50,400 INFO L185 FreeRefinementEngine]: Found 1 perfect and 0 imperfect interpolant sequences. [2023-03-31 23:06:50,400 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [5] imperfect sequences [] total 5 [2023-03-31 23:06:50,400 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1076967385] [2023-03-31 23:06:50,400 INFO L85 oduleStraightlineAll]: Using 1 perfect interpolants to construct interpolant automaton [2023-03-31 23:06:50,400 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 5 states [2023-03-31 23:06:50,401 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:06:50,401 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 5 interpolants. [2023-03-31 23:06:50,401 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=7, Invalid=13, Unknown=0, NotChecked=0, Total=20 [2023-03-31 23:06:50,401 INFO L87 Difference]: Start difference. First operand 35 states and 45 transitions. Second operand has 5 states, 4 states have (on average 4.5) internal successors, (18), 5 states have internal predecessors, (18), 3 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 2 states have call predecessors, (3), 3 states have call successors, (3) [2023-03-31 23:06:50,435 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:06:50,435 INFO L93 Difference]: Finished difference Result 60 states and 79 transitions. [2023-03-31 23:06:50,435 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 5 states. [2023-03-31 23:06:50,435 INFO L78 Accepts]: Start accepts. Automaton has has 5 states, 4 states have (on average 4.5) internal successors, (18), 5 states have internal predecessors, (18), 3 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 2 states have call predecessors, (3), 3 states have call successors, (3) Word has length 26 [2023-03-31 23:06:50,436 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:06:50,436 INFO L225 Difference]: With dead ends: 60 [2023-03-31 23:06:50,436 INFO L226 Difference]: Without dead ends: 36 [2023-03-31 23:06:50,437 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 6 GetRequests, 2 SyntacticMatches, 0 SemanticMatches, 4 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 0 ImplicationChecksByTransitivity, 0.0s TimeCoverageRelationStatistics Valid=11, Invalid=19, Unknown=0, NotChecked=0, Total=30 [2023-03-31 23:06:50,440 INFO L413 NwaCegarLoop]: 22 mSDtfsCounter, 5 mSDsluCounter, 51 mSDsCounter, 0 mSdLazyCounter, 39 mSolverCounterSat, 0 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.0s Time, 0 mProtectedPredicate, 0 mProtectedAction, 7 SdHoareTripleChecker+Valid, 73 SdHoareTripleChecker+Invalid, 39 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 0 IncrementalHoareTripleChecker+Valid, 39 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.0s IncrementalHoareTripleChecker+Time [2023-03-31 23:06:50,442 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [7 Valid, 73 Invalid, 39 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [0 Valid, 39 Invalid, 0 Unknown, 0 Unchecked, 0.0s Time] [2023-03-31 23:06:50,443 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 36 states. [2023-03-31 23:06:50,453 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 36 to 36. [2023-03-31 23:06:50,453 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 36 states, 24 states have (on average 1.4166666666666667) internal successors, (34), 26 states have internal predecessors, (34), 6 states have call successors, (6), 5 states have call predecessors, (6), 5 states have return successors, (6), 4 states have call predecessors, (6), 4 states have call successors, (6) [2023-03-31 23:06:50,454 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 36 states to 36 states and 46 transitions. [2023-03-31 23:06:50,454 INFO L78 Accepts]: Start accepts. Automaton has 36 states and 46 transitions. Word has length 26 [2023-03-31 23:06:50,454 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:06:50,454 INFO L495 AbstractCegarLoop]: Abstraction has 36 states and 46 transitions. [2023-03-31 23:06:50,454 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 5 states, 4 states have (on average 4.5) internal successors, (18), 5 states have internal predecessors, (18), 3 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 2 states have call predecessors, (3), 3 states have call successors, (3) [2023-03-31 23:06:50,454 INFO L276 IsEmpty]: Start isEmpty. Operand 36 states and 46 transitions. [2023-03-31 23:06:50,457 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 28 [2023-03-31 23:06:50,457 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:06:50,457 INFO L195 NwaCegarLoop]: trace histogram [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:06:50,457 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable5 [2023-03-31 23:06:50,457 INFO L420 AbstractCegarLoop]: === Iteration 7 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:06:50,458 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:06:50,458 INFO L85 PathProgramCache]: Analyzing trace with hash 129054403, now seen corresponding path program 1 times [2023-03-31 23:06:50,458 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:06:50,458 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1199365387] [2023-03-31 23:06:50,458 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:06:50,459 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:06:50,478 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:06:50,519 INFO L134 CoverageAnalysis]: Checked inductivity of 3 backedges. 0 proven. 0 refuted. 0 times theorem prover too weak. 3 trivial. 0 not checked. [2023-03-31 23:06:50,520 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:06:50,520 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1199365387] [2023-03-31 23:06:50,520 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1199365387] provided 1 perfect and 0 imperfect interpolant sequences [2023-03-31 23:06:50,520 INFO L185 FreeRefinementEngine]: Found 1 perfect and 0 imperfect interpolant sequences. [2023-03-31 23:06:50,520 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [5] imperfect sequences [] total 5 [2023-03-31 23:06:50,520 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [2071753755] [2023-03-31 23:06:50,520 INFO L85 oduleStraightlineAll]: Using 1 perfect interpolants to construct interpolant automaton [2023-03-31 23:06:50,520 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 5 states [2023-03-31 23:06:50,521 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:06:50,521 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 5 interpolants. [2023-03-31 23:06:50,521 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=7, Invalid=13, Unknown=0, NotChecked=0, Total=20 [2023-03-31 23:06:50,522 INFO L87 Difference]: Start difference. First operand 36 states and 46 transitions. Second operand has 5 states, 5 states have (on average 3.8) internal successors, (19), 5 states have internal predecessors, (19), 3 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:06:50,553 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:06:50,553 INFO L93 Difference]: Finished difference Result 43 states and 52 transitions. [2023-03-31 23:06:50,553 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 5 states. [2023-03-31 23:06:50,553 INFO L78 Accepts]: Start accepts. Automaton has has 5 states, 5 states have (on average 3.8) internal successors, (19), 5 states have internal predecessors, (19), 3 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) Word has length 27 [2023-03-31 23:06:50,554 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:06:50,556 INFO L225 Difference]: With dead ends: 43 [2023-03-31 23:06:50,556 INFO L226 Difference]: Without dead ends: 34 [2023-03-31 23:06:50,556 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 6 GetRequests, 2 SyntacticMatches, 0 SemanticMatches, 4 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 0 ImplicationChecksByTransitivity, 0.0s TimeCoverageRelationStatistics Valid=11, Invalid=19, Unknown=0, NotChecked=0, Total=30 [2023-03-31 23:06:50,558 INFO L413 NwaCegarLoop]: 22 mSDtfsCounter, 6 mSDsluCounter, 52 mSDsCounter, 0 mSdLazyCounter, 40 mSolverCounterSat, 0 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.0s Time, 0 mProtectedPredicate, 0 mProtectedAction, 7 SdHoareTripleChecker+Valid, 74 SdHoareTripleChecker+Invalid, 40 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 0 IncrementalHoareTripleChecker+Valid, 40 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.0s IncrementalHoareTripleChecker+Time [2023-03-31 23:06:50,558 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [7 Valid, 74 Invalid, 40 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [0 Valid, 40 Invalid, 0 Unknown, 0 Unchecked, 0.0s Time] [2023-03-31 23:06:50,560 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 34 states. [2023-03-31 23:06:50,565 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 34 to 34. [2023-03-31 23:06:50,566 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 34 states, 22 states have (on average 1.3636363636363635) internal successors, (30), 24 states have internal predecessors, (30), 6 states have call successors, (6), 5 states have call predecessors, (6), 5 states have return successors, (6), 4 states have call predecessors, (6), 4 states have call successors, (6) [2023-03-31 23:06:50,566 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 34 states to 34 states and 42 transitions. [2023-03-31 23:06:50,566 INFO L78 Accepts]: Start accepts. Automaton has 34 states and 42 transitions. Word has length 27 [2023-03-31 23:06:50,567 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:06:50,567 INFO L495 AbstractCegarLoop]: Abstraction has 34 states and 42 transitions. [2023-03-31 23:06:50,567 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 5 states, 5 states have (on average 3.8) internal successors, (19), 5 states have internal predecessors, (19), 3 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:06:50,567 INFO L276 IsEmpty]: Start isEmpty. Operand 34 states and 42 transitions. [2023-03-31 23:06:50,571 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 29 [2023-03-31 23:06:50,571 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:06:50,571 INFO L195 NwaCegarLoop]: trace histogram [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:06:50,571 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable6 [2023-03-31 23:06:50,571 INFO L420 AbstractCegarLoop]: === Iteration 8 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:06:50,571 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:06:50,571 INFO L85 PathProgramCache]: Analyzing trace with hash 1114189980, now seen corresponding path program 1 times [2023-03-31 23:06:50,571 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:06:50,571 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [865801337] [2023-03-31 23:06:50,571 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:06:50,572 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:06:50,587 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:06:50,648 INFO L134 CoverageAnalysis]: Checked inductivity of 4 backedges. 0 proven. 1 refuted. 0 times theorem prover too weak. 3 trivial. 0 not checked. [2023-03-31 23:06:50,648 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:06:50,649 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [865801337] [2023-03-31 23:06:50,649 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [865801337] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:06:50,649 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1040998735] [2023-03-31 23:06:50,649 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:06:50,649 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:06:50,649 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:06:50,662 INFO L229 MonitoredProcess]: Starting monitored process 2 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:06:50,666 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (2)] Waiting until timeout for monitored process [2023-03-31 23:06:50,714 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:06:50,715 INFO L262 TraceCheckSpWp]: Trace formula consists of 159 conjuncts, 4 conjunts are in the unsatisfiable core [2023-03-31 23:06:50,719 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:06:50,819 INFO L134 CoverageAnalysis]: Checked inductivity of 4 backedges. 1 proven. 0 refuted. 0 times theorem prover too weak. 3 trivial. 0 not checked. [2023-03-31 23:06:50,819 INFO L323 TraceCheckSpWp]: Omiting computation of backward sequence because forward sequence was already perfect [2023-03-31 23:06:50,819 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1040998735] provided 1 perfect and 0 imperfect interpolant sequences [2023-03-31 23:06:50,820 INFO L185 FreeRefinementEngine]: Found 1 perfect and 1 imperfect interpolant sequences. [2023-03-31 23:06:50,820 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [5] imperfect sequences [5] total 7 [2023-03-31 23:06:50,820 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1160335454] [2023-03-31 23:06:50,820 INFO L85 oduleStraightlineAll]: Using 1 perfect interpolants to construct interpolant automaton [2023-03-31 23:06:50,820 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 5 states [2023-03-31 23:06:50,820 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:06:50,821 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 5 interpolants. [2023-03-31 23:06:50,821 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=18, Invalid=24, Unknown=0, NotChecked=0, Total=42 [2023-03-31 23:06:50,821 INFO L87 Difference]: Start difference. First operand 34 states and 42 transitions. Second operand has 5 states, 5 states have (on average 4.0) internal successors, (20), 5 states have internal predecessors, (20), 2 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 2 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:06:50,851 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:06:50,851 INFO L93 Difference]: Finished difference Result 48 states and 57 transitions. [2023-03-31 23:06:50,851 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 5 states. [2023-03-31 23:06:50,851 INFO L78 Accepts]: Start accepts. Automaton has has 5 states, 5 states have (on average 4.0) internal successors, (20), 5 states have internal predecessors, (20), 2 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 2 states have call predecessors, (3), 2 states have call successors, (3) Word has length 28 [2023-03-31 23:06:50,851 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:06:50,852 INFO L225 Difference]: With dead ends: 48 [2023-03-31 23:06:50,852 INFO L226 Difference]: Without dead ends: 31 [2023-03-31 23:06:50,852 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 32 GetRequests, 27 SyntacticMatches, 0 SemanticMatches, 5 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 4 ImplicationChecksByTransitivity, 0.0s TimeCoverageRelationStatistics Valid=18, Invalid=24, Unknown=0, NotChecked=0, Total=42 [2023-03-31 23:06:50,852 INFO L413 NwaCegarLoop]: 21 mSDtfsCounter, 3 mSDsluCounter, 39 mSDsCounter, 0 mSdLazyCounter, 24 mSolverCounterSat, 0 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.0s Time, 0 mProtectedPredicate, 0 mProtectedAction, 3 SdHoareTripleChecker+Valid, 60 SdHoareTripleChecker+Invalid, 24 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 0 IncrementalHoareTripleChecker+Valid, 24 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.0s IncrementalHoareTripleChecker+Time [2023-03-31 23:06:50,853 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [3 Valid, 60 Invalid, 24 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [0 Valid, 24 Invalid, 0 Unknown, 0 Unchecked, 0.0s Time] [2023-03-31 23:06:50,853 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 31 states. [2023-03-31 23:06:50,855 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 31 to 29. [2023-03-31 23:06:50,855 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 29 states, 20 states have (on average 1.3) internal successors, (26), 20 states have internal predecessors, (26), 5 states have call successors, (5), 5 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 3 states have call successors, (3) [2023-03-31 23:06:50,855 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 29 states to 29 states and 34 transitions. [2023-03-31 23:06:50,855 INFO L78 Accepts]: Start accepts. Automaton has 29 states and 34 transitions. Word has length 28 [2023-03-31 23:06:50,855 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:06:50,855 INFO L495 AbstractCegarLoop]: Abstraction has 29 states and 34 transitions. [2023-03-31 23:06:50,855 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 5 states, 5 states have (on average 4.0) internal successors, (20), 5 states have internal predecessors, (20), 2 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 2 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:06:50,855 INFO L276 IsEmpty]: Start isEmpty. Operand 29 states and 34 transitions. [2023-03-31 23:06:50,856 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 29 [2023-03-31 23:06:50,856 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:06:50,856 INFO L195 NwaCegarLoop]: trace histogram [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:06:50,875 INFO L552 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (2)] Ended with exit code 0 [2023-03-31 23:06:51,056 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable7,2 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:06:51,056 INFO L420 AbstractCegarLoop]: === Iteration 9 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:06:51,057 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:06:51,057 INFO L85 PathProgramCache]: Analyzing trace with hash 1552146067, now seen corresponding path program 1 times [2023-03-31 23:06:51,057 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:06:51,057 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1423700455] [2023-03-31 23:06:51,057 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:06:51,057 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:06:51,066 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:06:51,101 INFO L134 CoverageAnalysis]: Checked inductivity of 4 backedges. 0 proven. 0 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:06:51,101 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:06:51,101 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1423700455] [2023-03-31 23:06:51,102 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1423700455] provided 1 perfect and 0 imperfect interpolant sequences [2023-03-31 23:06:51,102 INFO L185 FreeRefinementEngine]: Found 1 perfect and 0 imperfect interpolant sequences. [2023-03-31 23:06:51,102 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [5] imperfect sequences [] total 5 [2023-03-31 23:06:51,102 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [753944050] [2023-03-31 23:06:51,102 INFO L85 oduleStraightlineAll]: Using 1 perfect interpolants to construct interpolant automaton [2023-03-31 23:06:51,102 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 5 states [2023-03-31 23:06:51,102 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:06:51,103 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 5 interpolants. [2023-03-31 23:06:51,103 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=7, Invalid=13, Unknown=0, NotChecked=0, Total=20 [2023-03-31 23:06:51,103 INFO L87 Difference]: Start difference. First operand 29 states and 34 transitions. Second operand has 5 states, 5 states have (on average 4.0) internal successors, (20), 5 states have internal predecessors, (20), 3 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:06:51,130 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:06:51,131 INFO L93 Difference]: Finished difference Result 38 states and 44 transitions. [2023-03-31 23:06:51,131 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 5 states. [2023-03-31 23:06:51,131 INFO L78 Accepts]: Start accepts. Automaton has has 5 states, 5 states have (on average 4.0) internal successors, (20), 5 states have internal predecessors, (20), 3 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) Word has length 28 [2023-03-31 23:06:51,131 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:06:51,132 INFO L225 Difference]: With dead ends: 38 [2023-03-31 23:06:51,132 INFO L226 Difference]: Without dead ends: 30 [2023-03-31 23:06:51,132 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 6 GetRequests, 2 SyntacticMatches, 0 SemanticMatches, 4 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 0 ImplicationChecksByTransitivity, 0.0s TimeCoverageRelationStatistics Valid=11, Invalid=19, Unknown=0, NotChecked=0, Total=30 [2023-03-31 23:06:51,132 INFO L413 NwaCegarLoop]: 22 mSDtfsCounter, 5 mSDsluCounter, 51 mSDsCounter, 0 mSdLazyCounter, 39 mSolverCounterSat, 0 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.0s Time, 0 mProtectedPredicate, 0 mProtectedAction, 6 SdHoareTripleChecker+Valid, 73 SdHoareTripleChecker+Invalid, 39 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 0 IncrementalHoareTripleChecker+Valid, 39 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.0s IncrementalHoareTripleChecker+Time [2023-03-31 23:06:51,132 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [6 Valid, 73 Invalid, 39 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [0 Valid, 39 Invalid, 0 Unknown, 0 Unchecked, 0.0s Time] [2023-03-31 23:06:51,133 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 30 states. [2023-03-31 23:06:51,135 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 30 to 30. [2023-03-31 23:06:51,135 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 30 states, 21 states have (on average 1.2857142857142858) internal successors, (27), 21 states have internal predecessors, (27), 5 states have call successors, (5), 5 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 3 states have call successors, (3) [2023-03-31 23:06:51,135 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 30 states to 30 states and 35 transitions. [2023-03-31 23:06:51,135 INFO L78 Accepts]: Start accepts. Automaton has 30 states and 35 transitions. Word has length 28 [2023-03-31 23:06:51,135 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:06:51,135 INFO L495 AbstractCegarLoop]: Abstraction has 30 states and 35 transitions. [2023-03-31 23:06:51,136 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 5 states, 5 states have (on average 4.0) internal successors, (20), 5 states have internal predecessors, (20), 3 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:06:51,136 INFO L276 IsEmpty]: Start isEmpty. Operand 30 states and 35 transitions. [2023-03-31 23:06:51,136 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 30 [2023-03-31 23:06:51,136 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:06:51,136 INFO L195 NwaCegarLoop]: trace histogram [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:06:51,136 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable8 [2023-03-31 23:06:51,136 INFO L420 AbstractCegarLoop]: === Iteration 10 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:06:51,136 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:06:51,137 INFO L85 PathProgramCache]: Analyzing trace with hash 1648131948, now seen corresponding path program 1 times [2023-03-31 23:06:51,137 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:06:51,137 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1138027445] [2023-03-31 23:06:51,137 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:06:51,137 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:06:51,149 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:06:51,193 INFO L134 CoverageAnalysis]: Checked inductivity of 5 backedges. 0 proven. 1 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:06:51,194 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:06:51,194 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1138027445] [2023-03-31 23:06:51,194 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1138027445] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:06:51,194 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1178862130] [2023-03-31 23:06:51,194 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:06:51,194 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:06:51,194 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:06:51,195 INFO L229 MonitoredProcess]: Starting monitored process 3 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:06:51,213 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (3)] Waiting until timeout for monitored process [2023-03-31 23:06:51,257 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:06:51,258 INFO L262 TraceCheckSpWp]: Trace formula consists of 164 conjuncts, 4 conjunts are in the unsatisfiable core [2023-03-31 23:06:51,260 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:06:51,287 INFO L134 CoverageAnalysis]: Checked inductivity of 5 backedges. 1 proven. 0 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:06:51,288 INFO L323 TraceCheckSpWp]: Omiting computation of backward sequence because forward sequence was already perfect [2023-03-31 23:06:51,288 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1178862130] provided 1 perfect and 0 imperfect interpolant sequences [2023-03-31 23:06:51,288 INFO L185 FreeRefinementEngine]: Found 1 perfect and 1 imperfect interpolant sequences. [2023-03-31 23:06:51,288 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [5] imperfect sequences [5] total 7 [2023-03-31 23:06:51,288 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1233175094] [2023-03-31 23:06:51,288 INFO L85 oduleStraightlineAll]: Using 1 perfect interpolants to construct interpolant automaton [2023-03-31 23:06:51,288 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 5 states [2023-03-31 23:06:51,289 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:06:51,289 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 5 interpolants. [2023-03-31 23:06:51,289 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=18, Invalid=24, Unknown=0, NotChecked=0, Total=42 [2023-03-31 23:06:51,289 INFO L87 Difference]: Start difference. First operand 30 states and 35 transitions. Second operand has 5 states, 5 states have (on average 4.2) internal successors, (21), 5 states have internal predecessors, (21), 2 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 2 states have call predecessors, (3), 1 states have call successors, (3) [2023-03-31 23:06:51,305 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:06:51,305 INFO L93 Difference]: Finished difference Result 38 states and 43 transitions. [2023-03-31 23:06:51,305 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 5 states. [2023-03-31 23:06:51,305 INFO L78 Accepts]: Start accepts. Automaton has has 5 states, 5 states have (on average 4.2) internal successors, (21), 5 states have internal predecessors, (21), 2 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 2 states have call predecessors, (3), 1 states have call successors, (3) Word has length 29 [2023-03-31 23:06:51,305 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:06:51,306 INFO L225 Difference]: With dead ends: 38 [2023-03-31 23:06:51,306 INFO L226 Difference]: Without dead ends: 31 [2023-03-31 23:06:51,306 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 33 GetRequests, 28 SyntacticMatches, 0 SemanticMatches, 5 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 4 ImplicationChecksByTransitivity, 0.0s TimeCoverageRelationStatistics Valid=18, Invalid=24, Unknown=0, NotChecked=0, Total=42 [2023-03-31 23:06:51,306 INFO L413 NwaCegarLoop]: 21 mSDtfsCounter, 3 mSDsluCounter, 58 mSDsCounter, 0 mSdLazyCounter, 29 mSolverCounterSat, 0 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.0s Time, 0 mProtectedPredicate, 0 mProtectedAction, 3 SdHoareTripleChecker+Valid, 79 SdHoareTripleChecker+Invalid, 29 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 0 IncrementalHoareTripleChecker+Valid, 29 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.0s IncrementalHoareTripleChecker+Time [2023-03-31 23:06:51,306 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [3 Valid, 79 Invalid, 29 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [0 Valid, 29 Invalid, 0 Unknown, 0 Unchecked, 0.0s Time] [2023-03-31 23:06:51,307 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 31 states. [2023-03-31 23:06:51,309 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 31 to 31. [2023-03-31 23:06:51,309 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 31 states, 22 states have (on average 1.2727272727272727) internal successors, (28), 22 states have internal predecessors, (28), 5 states have call successors, (5), 5 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 3 states have call successors, (3) [2023-03-31 23:06:51,309 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 31 states to 31 states and 36 transitions. [2023-03-31 23:06:51,309 INFO L78 Accepts]: Start accepts. Automaton has 31 states and 36 transitions. Word has length 29 [2023-03-31 23:06:51,309 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:06:51,309 INFO L495 AbstractCegarLoop]: Abstraction has 31 states and 36 transitions. [2023-03-31 23:06:51,309 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 5 states, 5 states have (on average 4.2) internal successors, (21), 5 states have internal predecessors, (21), 2 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 2 states have call predecessors, (3), 1 states have call successors, (3) [2023-03-31 23:06:51,310 INFO L276 IsEmpty]: Start isEmpty. Operand 31 states and 36 transitions. [2023-03-31 23:06:51,310 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 31 [2023-03-31 23:06:51,310 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:06:51,310 INFO L195 NwaCegarLoop]: trace histogram [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:06:51,327 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (3)] Forceful destruction successful, exit code 0 [2023-03-31 23:06:51,514 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: 3 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true,SelfDestructingSolverStorable9 [2023-03-31 23:06:51,515 INFO L420 AbstractCegarLoop]: === Iteration 11 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:06:51,515 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:06:51,515 INFO L85 PathProgramCache]: Analyzing trace with hash -1796768036, now seen corresponding path program 1 times [2023-03-31 23:06:51,516 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:06:51,516 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1087427513] [2023-03-31 23:06:51,516 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:06:51,516 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:06:51,526 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:06:51,807 INFO L134 CoverageAnalysis]: Checked inductivity of 6 backedges. 0 proven. 4 refuted. 0 times theorem prover too weak. 2 trivial. 0 not checked. [2023-03-31 23:06:51,807 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:06:51,807 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1087427513] [2023-03-31 23:06:51,808 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1087427513] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:06:51,808 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [419075881] [2023-03-31 23:06:51,808 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:06:51,809 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:06:51,809 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:06:51,809 INFO L229 MonitoredProcess]: Starting monitored process 4 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:06:51,811 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (4)] Waiting until timeout for monitored process [2023-03-31 23:06:51,854 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:06:51,856 INFO L262 TraceCheckSpWp]: Trace formula consists of 169 conjuncts, 34 conjunts are in the unsatisfiable core [2023-03-31 23:06:51,857 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:06:52,030 INFO L134 CoverageAnalysis]: Checked inductivity of 6 backedges. 0 proven. 4 refuted. 0 times theorem prover too weak. 2 trivial. 0 not checked. [2023-03-31 23:06:52,030 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-03-31 23:06:52,217 INFO L134 CoverageAnalysis]: Checked inductivity of 6 backedges. 0 proven. 4 refuted. 0 times theorem prover too weak. 2 trivial. 0 not checked. [2023-03-31 23:06:52,217 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [419075881] provided 0 perfect and 2 imperfect interpolant sequences [2023-03-31 23:06:52,217 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [1039300129] [2023-03-31 23:06:52,232 INFO L159 IcfgInterpreter]: Started Sifa with 25 locations of interest [2023-03-31 23:06:52,232 INFO L166 IcfgInterpreter]: Building call graph [2023-03-31 23:06:52,236 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2023-03-31 23:06:52,239 INFO L176 IcfgInterpreter]: Starting interpretation [2023-03-31 23:06:52,239 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2023-03-31 23:06:52,275 INFO L197 IcfgInterpreter]: Interpreting procedure main with input of size 8 for LOIs [2023-03-31 23:06:52,378 INFO L197 IcfgInterpreter]: Interpreting procedure __VERIFIER_assert with input of size 26 for LOIs [2023-03-31 23:06:52,389 INFO L197 IcfgInterpreter]: Interpreting procedure student_version with input of size 19 for LOIs [2023-03-31 23:06:52,438 INFO L197 IcfgInterpreter]: Interpreting procedure correct_version with input of size 19 for LOIs [2023-03-31 23:06:52,488 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.init with input of size 7 for LOIs [2023-03-31 23:06:52,492 INFO L180 IcfgInterpreter]: Interpretation finished [2023-03-31 23:06:53,589 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '1766#(and (= |__VERIFIER_assert_#in~cond| 0) (= __VERIFIER_assert_~cond 0) (= |#NULL.offset| 0) (<= 0 |#StackHeapBarrier|) (= |#NULL.base| 0))' at error location [2023-03-31 23:06:53,589 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2023-03-31 23:06:53,589 INFO L185 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2023-03-31 23:06:53,590 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [18, 18, 18] total 24 [2023-03-31 23:06:53,590 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [728693929] [2023-03-31 23:06:53,590 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2023-03-31 23:06:53,590 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 24 states [2023-03-31 23:06:53,590 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:06:53,591 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 24 interpolants. [2023-03-31 23:06:53,591 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=143, Invalid=1927, Unknown=0, NotChecked=0, Total=2070 [2023-03-31 23:06:53,591 INFO L87 Difference]: Start difference. First operand 31 states and 36 transitions. Second operand has 24 states, 19 states have (on average 1.5263157894736843) internal successors, (29), 19 states have internal predecessors, (29), 4 states have call successors, (6), 3 states have call predecessors, (6), 3 states have return successors, (4), 4 states have call predecessors, (4), 2 states have call successors, (4) [2023-03-31 23:06:53,818 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:06:53,819 INFO L93 Difference]: Finished difference Result 53 states and 66 transitions. [2023-03-31 23:06:53,819 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 19 states. [2023-03-31 23:06:53,819 INFO L78 Accepts]: Start accepts. Automaton has has 24 states, 19 states have (on average 1.5263157894736843) internal successors, (29), 19 states have internal predecessors, (29), 4 states have call successors, (6), 3 states have call predecessors, (6), 3 states have return successors, (4), 4 states have call predecessors, (4), 2 states have call successors, (4) Word has length 30 [2023-03-31 23:06:53,819 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:06:53,820 INFO L225 Difference]: With dead ends: 53 [2023-03-31 23:06:53,820 INFO L226 Difference]: Without dead ends: 47 [2023-03-31 23:06:53,821 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 113 GetRequests, 56 SyntacticMatches, 7 SemanticMatches, 50 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 513 ImplicationChecksByTransitivity, 1.4s TimeCoverageRelationStatistics Valid=173, Invalid=2479, Unknown=0, NotChecked=0, Total=2652 [2023-03-31 23:06:53,821 INFO L413 NwaCegarLoop]: 16 mSDtfsCounter, 16 mSDsluCounter, 287 mSDsCounter, 0 mSdLazyCounter, 432 mSolverCounterSat, 1 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.1s Time, 0 mProtectedPredicate, 0 mProtectedAction, 21 SdHoareTripleChecker+Valid, 303 SdHoareTripleChecker+Invalid, 433 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 1 IncrementalHoareTripleChecker+Valid, 432 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.1s IncrementalHoareTripleChecker+Time [2023-03-31 23:06:53,821 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [21 Valid, 303 Invalid, 433 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [1 Valid, 432 Invalid, 0 Unknown, 0 Unchecked, 0.1s Time] [2023-03-31 23:06:53,821 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 47 states. [2023-03-31 23:06:53,825 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 47 to 41. [2023-03-31 23:06:53,825 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 41 states, 29 states have (on average 1.3448275862068966) internal successors, (39), 31 states have internal predecessors, (39), 6 states have call successors, (6), 5 states have call predecessors, (6), 5 states have return successors, (6), 4 states have call predecessors, (6), 4 states have call successors, (6) [2023-03-31 23:06:53,825 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 41 states to 41 states and 51 transitions. [2023-03-31 23:06:53,825 INFO L78 Accepts]: Start accepts. Automaton has 41 states and 51 transitions. Word has length 30 [2023-03-31 23:06:53,825 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:06:53,826 INFO L495 AbstractCegarLoop]: Abstraction has 41 states and 51 transitions. [2023-03-31 23:06:53,826 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 24 states, 19 states have (on average 1.5263157894736843) internal successors, (29), 19 states have internal predecessors, (29), 4 states have call successors, (6), 3 states have call predecessors, (6), 3 states have return successors, (4), 4 states have call predecessors, (4), 2 states have call successors, (4) [2023-03-31 23:06:53,826 INFO L276 IsEmpty]: Start isEmpty. Operand 41 states and 51 transitions. [2023-03-31 23:06:53,826 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 32 [2023-03-31 23:06:53,826 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:06:53,826 INFO L195 NwaCegarLoop]: trace histogram [2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:06:53,831 INFO L552 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (4)] Ended with exit code 0 [2023-03-31 23:06:54,030 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable10,4 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:06:54,031 INFO L420 AbstractCegarLoop]: === Iteration 12 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:06:54,031 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:06:54,031 INFO L85 PathProgramCache]: Analyzing trace with hash -1214485140, now seen corresponding path program 2 times [2023-03-31 23:06:54,031 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:06:54,031 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1809155520] [2023-03-31 23:06:54,032 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:06:54,032 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:06:54,039 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:06:54,068 INFO L134 CoverageAnalysis]: Checked inductivity of 8 backedges. 2 proven. 2 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:06:54,068 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:06:54,069 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1809155520] [2023-03-31 23:06:54,069 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1809155520] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:06:54,069 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1384815492] [2023-03-31 23:06:54,069 INFO L93 rtionOrderModulation]: Changing assertion order to OUTSIDE_LOOP_FIRST2 [2023-03-31 23:06:54,069 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:06:54,069 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:06:54,085 INFO L229 MonitoredProcess]: Starting monitored process 5 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:06:54,101 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (5)] Waiting until timeout for monitored process [2023-03-31 23:06:54,139 INFO L228 tOrderPrioritization]: Assert order OUTSIDE_LOOP_FIRST2 issued 2 check-sat command(s) [2023-03-31 23:06:54,139 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2023-03-31 23:06:54,140 INFO L262 TraceCheckSpWp]: Trace formula consists of 174 conjuncts, 5 conjunts are in the unsatisfiable core [2023-03-31 23:06:54,141 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:06:54,167 INFO L134 CoverageAnalysis]: Checked inductivity of 8 backedges. 3 proven. 1 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:06:54,167 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-03-31 23:06:54,205 INFO L134 CoverageAnalysis]: Checked inductivity of 8 backedges. 3 proven. 1 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:06:54,205 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1384815492] provided 0 perfect and 2 imperfect interpolant sequences [2023-03-31 23:06:54,205 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [465271508] [2023-03-31 23:06:54,207 INFO L159 IcfgInterpreter]: Started Sifa with 25 locations of interest [2023-03-31 23:06:54,207 INFO L166 IcfgInterpreter]: Building call graph [2023-03-31 23:06:54,207 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2023-03-31 23:06:54,208 INFO L176 IcfgInterpreter]: Starting interpretation [2023-03-31 23:06:54,208 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2023-03-31 23:06:54,237 INFO L197 IcfgInterpreter]: Interpreting procedure main with input of size 8 for LOIs [2023-03-31 23:06:54,346 INFO L197 IcfgInterpreter]: Interpreting procedure __VERIFIER_assert with input of size 26 for LOIs [2023-03-31 23:06:54,354 INFO L197 IcfgInterpreter]: Interpreting procedure student_version with input of size 19 for LOIs [2023-03-31 23:06:54,388 INFO L197 IcfgInterpreter]: Interpreting procedure correct_version with input of size 19 for LOIs [2023-03-31 23:06:54,421 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.init with input of size 7 for LOIs [2023-03-31 23:06:54,423 INFO L180 IcfgInterpreter]: Interpretation finished [2023-03-31 23:06:55,170 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '2150#(and (= |__VERIFIER_assert_#in~cond| 0) (= __VERIFIER_assert_~cond 0) (= |#NULL.offset| 0) (<= 0 |#StackHeapBarrier|) (= |#NULL.base| 0))' at error location [2023-03-31 23:06:55,170 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2023-03-31 23:06:55,170 INFO L185 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2023-03-31 23:06:55,171 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [6, 6, 6] total 10 [2023-03-31 23:06:55,171 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [706257145] [2023-03-31 23:06:55,171 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2023-03-31 23:06:55,171 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 10 states [2023-03-31 23:06:55,171 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:06:55,172 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 10 interpolants. [2023-03-31 23:06:55,172 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=116, Invalid=876, Unknown=0, NotChecked=0, Total=992 [2023-03-31 23:06:55,172 INFO L87 Difference]: Start difference. First operand 41 states and 51 transitions. Second operand has 10 states, 10 states have (on average 3.0) internal successors, (30), 10 states have internal predecessors, (30), 2 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 2 states have call predecessors, (3), 1 states have call successors, (3) [2023-03-31 23:06:55,197 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:06:55,197 INFO L93 Difference]: Finished difference Result 59 states and 76 transitions. [2023-03-31 23:06:55,197 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 7 states. [2023-03-31 23:06:55,197 INFO L78 Accepts]: Start accepts. Automaton has has 10 states, 10 states have (on average 3.0) internal successors, (30), 10 states have internal predecessors, (30), 2 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 2 states have call predecessors, (3), 1 states have call successors, (3) Word has length 31 [2023-03-31 23:06:55,198 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:06:55,198 INFO L225 Difference]: With dead ends: 59 [2023-03-31 23:06:55,198 INFO L226 Difference]: Without dead ends: 51 [2023-03-31 23:06:55,198 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 98 GetRequests, 66 SyntacticMatches, 2 SemanticMatches, 30 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 297 ImplicationChecksByTransitivity, 0.8s TimeCoverageRelationStatistics Valid=116, Invalid=876, Unknown=0, NotChecked=0, Total=992 [2023-03-31 23:06:55,199 INFO L413 NwaCegarLoop]: 21 mSDtfsCounter, 2 mSDsluCounter, 100 mSDsCounter, 0 mSdLazyCounter, 57 mSolverCounterSat, 1 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.0s Time, 0 mProtectedPredicate, 0 mProtectedAction, 2 SdHoareTripleChecker+Valid, 121 SdHoareTripleChecker+Invalid, 58 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 1 IncrementalHoareTripleChecker+Valid, 57 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.0s IncrementalHoareTripleChecker+Time [2023-03-31 23:06:55,199 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [2 Valid, 121 Invalid, 58 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [1 Valid, 57 Invalid, 0 Unknown, 0 Unchecked, 0.0s Time] [2023-03-31 23:06:55,199 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 51 states. [2023-03-31 23:06:55,202 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 51 to 49. [2023-03-31 23:06:55,203 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 49 states, 37 states have (on average 1.3513513513513513) internal successors, (50), 39 states have internal predecessors, (50), 6 states have call successors, (6), 5 states have call predecessors, (6), 5 states have return successors, (6), 4 states have call predecessors, (6), 4 states have call successors, (6) [2023-03-31 23:06:55,203 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 49 states to 49 states and 62 transitions. [2023-03-31 23:06:55,203 INFO L78 Accepts]: Start accepts. Automaton has 49 states and 62 transitions. Word has length 31 [2023-03-31 23:06:55,203 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:06:55,203 INFO L495 AbstractCegarLoop]: Abstraction has 49 states and 62 transitions. [2023-03-31 23:06:55,203 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 10 states, 10 states have (on average 3.0) internal successors, (30), 10 states have internal predecessors, (30), 2 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 2 states have call predecessors, (3), 1 states have call successors, (3) [2023-03-31 23:06:55,203 INFO L276 IsEmpty]: Start isEmpty. Operand 49 states and 62 transitions. [2023-03-31 23:06:55,205 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 32 [2023-03-31 23:06:55,205 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:06:55,206 INFO L195 NwaCegarLoop]: trace histogram [2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:06:55,213 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (5)] Forceful destruction successful, exit code 0 [2023-03-31 23:06:55,410 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable11,5 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:06:55,411 INFO L420 AbstractCegarLoop]: === Iteration 13 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:06:55,411 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:06:55,411 INFO L85 PathProgramCache]: Analyzing trace with hash 251350389, now seen corresponding path program 3 times [2023-03-31 23:06:55,411 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:06:55,411 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [108925981] [2023-03-31 23:06:55,411 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:06:55,412 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:06:55,418 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:06:55,541 INFO L134 CoverageAnalysis]: Checked inductivity of 8 backedges. 0 proven. 4 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:06:55,542 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:06:55,542 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [108925981] [2023-03-31 23:06:55,542 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [108925981] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:06:55,542 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [575293897] [2023-03-31 23:06:55,542 INFO L93 rtionOrderModulation]: Changing assertion order to TERMS_WITH_SMALL_CONSTANTS_FIRST [2023-03-31 23:06:55,542 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:06:55,542 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:06:55,543 INFO L229 MonitoredProcess]: Starting monitored process 6 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:06:55,565 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (6)] Waiting until timeout for monitored process [2023-03-31 23:06:55,604 INFO L228 tOrderPrioritization]: Assert order TERMS_WITH_SMALL_CONSTANTS_FIRST issued 0 check-sat command(s) [2023-03-31 23:06:55,604 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2023-03-31 23:06:55,605 INFO L262 TraceCheckSpWp]: Trace formula consists of 125 conjuncts, 14 conjunts are in the unsatisfiable core [2023-03-31 23:06:55,607 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:06:55,702 INFO L134 CoverageAnalysis]: Checked inductivity of 8 backedges. 0 proven. 4 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:06:55,702 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-03-31 23:06:55,956 INFO L134 CoverageAnalysis]: Checked inductivity of 8 backedges. 2 proven. 2 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:06:55,956 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [575293897] provided 0 perfect and 2 imperfect interpolant sequences [2023-03-31 23:06:55,956 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [1774946199] [2023-03-31 23:06:55,958 INFO L159 IcfgInterpreter]: Started Sifa with 25 locations of interest [2023-03-31 23:06:55,958 INFO L166 IcfgInterpreter]: Building call graph [2023-03-31 23:06:55,958 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2023-03-31 23:06:55,958 INFO L176 IcfgInterpreter]: Starting interpretation [2023-03-31 23:06:55,958 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2023-03-31 23:06:55,971 INFO L197 IcfgInterpreter]: Interpreting procedure main with input of size 8 for LOIs [2023-03-31 23:06:56,050 INFO L197 IcfgInterpreter]: Interpreting procedure __VERIFIER_assert with input of size 26 for LOIs [2023-03-31 23:06:56,056 INFO L197 IcfgInterpreter]: Interpreting procedure student_version with input of size 19 for LOIs [2023-03-31 23:06:56,097 INFO L197 IcfgInterpreter]: Interpreting procedure correct_version with input of size 19 for LOIs [2023-03-31 23:06:56,125 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.init with input of size 7 for LOIs [2023-03-31 23:06:56,127 INFO L180 IcfgInterpreter]: Interpretation finished [2023-03-31 23:06:57,122 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '2557#(and (= |__VERIFIER_assert_#in~cond| 0) (= __VERIFIER_assert_~cond 0) (= |#NULL.offset| 0) (<= 0 |#StackHeapBarrier|) (= |#NULL.base| 0))' at error location [2023-03-31 23:06:57,122 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2023-03-31 23:06:57,122 INFO L185 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2023-03-31 23:06:57,123 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [9, 9, 9] total 17 [2023-03-31 23:06:57,123 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [2003289695] [2023-03-31 23:06:57,123 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2023-03-31 23:06:57,123 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 17 states [2023-03-31 23:06:57,123 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:06:57,123 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 17 interpolants. [2023-03-31 23:06:57,125 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=131, Invalid=1351, Unknown=0, NotChecked=0, Total=1482 [2023-03-31 23:06:57,125 INFO L87 Difference]: Start difference. First operand 49 states and 62 transitions. Second operand has 17 states, 17 states have (on average 2.5294117647058822) internal successors, (43), 17 states have internal predecessors, (43), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:06:57,274 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:06:57,274 INFO L93 Difference]: Finished difference Result 63 states and 81 transitions. [2023-03-31 23:06:57,274 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 9 states. [2023-03-31 23:06:57,274 INFO L78 Accepts]: Start accepts. Automaton has has 17 states, 17 states have (on average 2.5294117647058822) internal successors, (43), 17 states have internal predecessors, (43), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) Word has length 31 [2023-03-31 23:06:57,275 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:06:57,275 INFO L225 Difference]: With dead ends: 63 [2023-03-31 23:06:57,275 INFO L226 Difference]: Without dead ends: 57 [2023-03-31 23:06:57,276 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 103 GetRequests, 61 SyntacticMatches, 3 SemanticMatches, 39 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 323 ImplicationChecksByTransitivity, 1.2s TimeCoverageRelationStatistics Valid=144, Invalid=1496, Unknown=0, NotChecked=0, Total=1640 [2023-03-31 23:06:57,276 INFO L413 NwaCegarLoop]: 19 mSDtfsCounter, 13 mSDsluCounter, 158 mSDsCounter, 0 mSdLazyCounter, 205 mSolverCounterSat, 1 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.1s Time, 0 mProtectedPredicate, 0 mProtectedAction, 14 SdHoareTripleChecker+Valid, 177 SdHoareTripleChecker+Invalid, 206 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 1 IncrementalHoareTripleChecker+Valid, 205 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.1s IncrementalHoareTripleChecker+Time [2023-03-31 23:06:57,276 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [14 Valid, 177 Invalid, 206 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [1 Valid, 205 Invalid, 0 Unknown, 0 Unchecked, 0.1s Time] [2023-03-31 23:06:57,277 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 57 states. [2023-03-31 23:06:57,281 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 57 to 55. [2023-03-31 23:06:57,281 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 55 states, 40 states have (on average 1.375) internal successors, (55), 44 states have internal predecessors, (55), 7 states have call successors, (7), 5 states have call predecessors, (7), 7 states have return successors, (10), 5 states have call predecessors, (10), 5 states have call successors, (10) [2023-03-31 23:06:57,281 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 55 states to 55 states and 72 transitions. [2023-03-31 23:06:57,281 INFO L78 Accepts]: Start accepts. Automaton has 55 states and 72 transitions. Word has length 31 [2023-03-31 23:06:57,281 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:06:57,281 INFO L495 AbstractCegarLoop]: Abstraction has 55 states and 72 transitions. [2023-03-31 23:06:57,281 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 17 states, 17 states have (on average 2.5294117647058822) internal successors, (43), 17 states have internal predecessors, (43), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:06:57,282 INFO L276 IsEmpty]: Start isEmpty. Operand 55 states and 72 transitions. [2023-03-31 23:06:57,282 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 32 [2023-03-31 23:06:57,282 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:06:57,282 INFO L195 NwaCegarLoop]: trace histogram [2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:06:57,294 INFO L552 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (6)] Ended with exit code 0 [2023-03-31 23:06:57,486 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: 6 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true,SelfDestructingSolverStorable12 [2023-03-31 23:06:57,487 INFO L420 AbstractCegarLoop]: === Iteration 14 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:06:57,487 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:06:57,487 INFO L85 PathProgramCache]: Analyzing trace with hash 2024093845, now seen corresponding path program 4 times [2023-03-31 23:06:57,487 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:06:57,487 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1593686889] [2023-03-31 23:06:57,487 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:06:57,487 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:06:57,505 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:06:57,556 INFO L134 CoverageAnalysis]: Checked inductivity of 8 backedges. 2 proven. 2 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:06:57,556 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:06:57,557 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1593686889] [2023-03-31 23:06:57,557 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1593686889] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:06:57,557 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [421598176] [2023-03-31 23:06:57,557 INFO L93 rtionOrderModulation]: Changing assertion order to NOT_INCREMENTALLY [2023-03-31 23:06:57,557 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:06:57,557 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:06:57,558 INFO L229 MonitoredProcess]: Starting monitored process 7 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:06:57,560 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (7)] Waiting until timeout for monitored process [2023-03-31 23:06:57,601 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:06:57,601 INFO L262 TraceCheckSpWp]: Trace formula consists of 174 conjuncts, 5 conjunts are in the unsatisfiable core [2023-03-31 23:06:57,605 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:06:57,628 INFO L134 CoverageAnalysis]: Checked inductivity of 8 backedges. 3 proven. 1 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:06:57,629 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-03-31 23:06:57,651 INFO L134 CoverageAnalysis]: Checked inductivity of 8 backedges. 3 proven. 1 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:06:57,651 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [421598176] provided 0 perfect and 2 imperfect interpolant sequences [2023-03-31 23:06:57,651 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [1274356828] [2023-03-31 23:06:57,654 INFO L159 IcfgInterpreter]: Started Sifa with 25 locations of interest [2023-03-31 23:06:57,654 INFO L166 IcfgInterpreter]: Building call graph [2023-03-31 23:06:57,655 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2023-03-31 23:06:57,655 INFO L176 IcfgInterpreter]: Starting interpretation [2023-03-31 23:06:57,655 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2023-03-31 23:06:57,676 INFO L197 IcfgInterpreter]: Interpreting procedure main with input of size 8 for LOIs [2023-03-31 23:06:57,740 INFO L197 IcfgInterpreter]: Interpreting procedure __VERIFIER_assert with input of size 26 for LOIs [2023-03-31 23:06:57,746 INFO L197 IcfgInterpreter]: Interpreting procedure student_version with input of size 19 for LOIs [2023-03-31 23:06:57,773 INFO L197 IcfgInterpreter]: Interpreting procedure correct_version with input of size 19 for LOIs [2023-03-31 23:06:57,800 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.init with input of size 7 for LOIs [2023-03-31 23:06:57,802 INFO L180 IcfgInterpreter]: Interpretation finished [2023-03-31 23:06:58,618 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '2977#(and (= |__VERIFIER_assert_#in~cond| 0) (= __VERIFIER_assert_~cond 0) (= |#NULL.offset| 0) (<= 0 |#StackHeapBarrier|) (= |#NULL.base| 0))' at error location [2023-03-31 23:06:58,618 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2023-03-31 23:06:58,618 INFO L185 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2023-03-31 23:06:58,619 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [6, 6, 6] total 10 [2023-03-31 23:06:58,619 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [787606591] [2023-03-31 23:06:58,619 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2023-03-31 23:06:58,619 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 10 states [2023-03-31 23:06:58,619 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:06:58,620 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 10 interpolants. [2023-03-31 23:06:58,620 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=116, Invalid=876, Unknown=0, NotChecked=0, Total=992 [2023-03-31 23:06:58,620 INFO L87 Difference]: Start difference. First operand 55 states and 72 transitions. Second operand has 10 states, 10 states have (on average 3.7) internal successors, (37), 10 states have internal predecessors, (37), 2 states have call successors, (6), 2 states have call predecessors, (6), 2 states have return successors, (4), 2 states have call predecessors, (4), 2 states have call successors, (4) [2023-03-31 23:06:58,662 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:06:58,662 INFO L93 Difference]: Finished difference Result 101 states and 135 transitions. [2023-03-31 23:06:58,663 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 7 states. [2023-03-31 23:06:58,663 INFO L78 Accepts]: Start accepts. Automaton has has 10 states, 10 states have (on average 3.7) internal successors, (37), 10 states have internal predecessors, (37), 2 states have call successors, (6), 2 states have call predecessors, (6), 2 states have return successors, (4), 2 states have call predecessors, (4), 2 states have call successors, (4) Word has length 31 [2023-03-31 23:06:58,663 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:06:58,663 INFO L225 Difference]: With dead ends: 101 [2023-03-31 23:06:58,663 INFO L226 Difference]: Without dead ends: 65 [2023-03-31 23:06:58,664 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 98 GetRequests, 66 SyntacticMatches, 2 SemanticMatches, 30 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 297 ImplicationChecksByTransitivity, 0.8s TimeCoverageRelationStatistics Valid=116, Invalid=876, Unknown=0, NotChecked=0, Total=992 [2023-03-31 23:06:58,664 INFO L413 NwaCegarLoop]: 21 mSDtfsCounter, 3 mSDsluCounter, 100 mSDsCounter, 0 mSdLazyCounter, 57 mSolverCounterSat, 1 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.0s Time, 0 mProtectedPredicate, 0 mProtectedAction, 3 SdHoareTripleChecker+Valid, 121 SdHoareTripleChecker+Invalid, 58 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 1 IncrementalHoareTripleChecker+Valid, 57 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.0s IncrementalHoareTripleChecker+Time [2023-03-31 23:06:58,664 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [3 Valid, 121 Invalid, 58 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [1 Valid, 57 Invalid, 0 Unknown, 0 Unchecked, 0.0s Time] [2023-03-31 23:06:58,665 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 65 states. [2023-03-31 23:06:58,669 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 65 to 63. [2023-03-31 23:06:58,670 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 63 states, 48 states have (on average 1.375) internal successors, (66), 52 states have internal predecessors, (66), 7 states have call successors, (7), 5 states have call predecessors, (7), 7 states have return successors, (10), 5 states have call predecessors, (10), 5 states have call successors, (10) [2023-03-31 23:06:58,670 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 63 states to 63 states and 83 transitions. [2023-03-31 23:06:58,670 INFO L78 Accepts]: Start accepts. Automaton has 63 states and 83 transitions. Word has length 31 [2023-03-31 23:06:58,670 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:06:58,670 INFO L495 AbstractCegarLoop]: Abstraction has 63 states and 83 transitions. [2023-03-31 23:06:58,670 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 10 states, 10 states have (on average 3.7) internal successors, (37), 10 states have internal predecessors, (37), 2 states have call successors, (6), 2 states have call predecessors, (6), 2 states have return successors, (4), 2 states have call predecessors, (4), 2 states have call successors, (4) [2023-03-31 23:06:58,670 INFO L276 IsEmpty]: Start isEmpty. Operand 63 states and 83 transitions. [2023-03-31 23:06:58,671 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 32 [2023-03-31 23:06:58,671 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:06:58,671 INFO L195 NwaCegarLoop]: trace histogram [2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:06:58,678 INFO L552 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (7)] Ended with exit code 0 [2023-03-31 23:06:58,875 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable13,7 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:06:58,875 INFO L420 AbstractCegarLoop]: === Iteration 15 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:06:58,876 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:06:58,876 INFO L85 PathProgramCache]: Analyzing trace with hash -559274524, now seen corresponding path program 5 times [2023-03-31 23:06:58,876 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:06:58,876 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [2115803509] [2023-03-31 23:06:58,876 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:06:58,876 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:06:58,882 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:06:58,954 INFO L134 CoverageAnalysis]: Checked inductivity of 8 backedges. 0 proven. 4 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:06:58,955 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:06:58,955 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [2115803509] [2023-03-31 23:06:58,955 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [2115803509] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:06:58,955 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1859795187] [2023-03-31 23:06:58,955 INFO L93 rtionOrderModulation]: Changing assertion order to OUTSIDE_LOOP_FIRST2 [2023-03-31 23:06:58,955 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:06:58,955 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:06:58,973 INFO L229 MonitoredProcess]: Starting monitored process 8 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:06:59,004 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (8)] Waiting until timeout for monitored process [2023-03-31 23:06:59,022 INFO L228 tOrderPrioritization]: Assert order OUTSIDE_LOOP_FIRST2 issued 2 check-sat command(s) [2023-03-31 23:06:59,022 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2023-03-31 23:06:59,023 INFO L262 TraceCheckSpWp]: Trace formula consists of 174 conjuncts, 14 conjunts are in the unsatisfiable core [2023-03-31 23:06:59,024 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:06:59,112 INFO L134 CoverageAnalysis]: Checked inductivity of 8 backedges. 0 proven. 4 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:06:59,112 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-03-31 23:06:59,264 INFO L134 CoverageAnalysis]: Checked inductivity of 8 backedges. 2 proven. 2 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:06:59,264 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1859795187] provided 0 perfect and 2 imperfect interpolant sequences [2023-03-31 23:06:59,264 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [802955817] [2023-03-31 23:06:59,265 INFO L159 IcfgInterpreter]: Started Sifa with 25 locations of interest [2023-03-31 23:06:59,265 INFO L166 IcfgInterpreter]: Building call graph [2023-03-31 23:06:59,266 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2023-03-31 23:06:59,266 INFO L176 IcfgInterpreter]: Starting interpretation [2023-03-31 23:06:59,266 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2023-03-31 23:06:59,274 INFO L197 IcfgInterpreter]: Interpreting procedure main with input of size 8 for LOIs [2023-03-31 23:06:59,331 INFO L197 IcfgInterpreter]: Interpreting procedure __VERIFIER_assert with input of size 26 for LOIs [2023-03-31 23:06:59,338 INFO L197 IcfgInterpreter]: Interpreting procedure student_version with input of size 19 for LOIs [2023-03-31 23:06:59,365 INFO L197 IcfgInterpreter]: Interpreting procedure correct_version with input of size 19 for LOIs [2023-03-31 23:06:59,403 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.init with input of size 7 for LOIs [2023-03-31 23:06:59,405 INFO L180 IcfgInterpreter]: Interpretation finished [2023-03-31 23:07:00,198 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '3484#(and (= |__VERIFIER_assert_#in~cond| 0) (= __VERIFIER_assert_~cond 0) (= |#NULL.offset| 0) (<= 0 |#StackHeapBarrier|) (= |#NULL.base| 0))' at error location [2023-03-31 23:07:00,198 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2023-03-31 23:07:00,198 INFO L185 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2023-03-31 23:07:00,198 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [9, 9, 9] total 17 [2023-03-31 23:07:00,198 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1853003189] [2023-03-31 23:07:00,198 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2023-03-31 23:07:00,199 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 17 states [2023-03-31 23:07:00,199 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:07:00,199 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 17 interpolants. [2023-03-31 23:07:00,199 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=130, Invalid=1352, Unknown=0, NotChecked=0, Total=1482 [2023-03-31 23:07:00,200 INFO L87 Difference]: Start difference. First operand 63 states and 83 transitions. Second operand has 17 states, 17 states have (on average 2.5294117647058822) internal successors, (43), 17 states have internal predecessors, (43), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:07:00,377 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:07:00,377 INFO L93 Difference]: Finished difference Result 71 states and 90 transitions. [2023-03-31 23:07:00,401 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 10 states. [2023-03-31 23:07:00,401 INFO L78 Accepts]: Start accepts. Automaton has has 17 states, 17 states have (on average 2.5294117647058822) internal successors, (43), 17 states have internal predecessors, (43), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) Word has length 31 [2023-03-31 23:07:00,401 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:07:00,403 INFO L225 Difference]: With dead ends: 71 [2023-03-31 23:07:00,403 INFO L226 Difference]: Without dead ends: 65 [2023-03-31 23:07:00,405 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 106 GetRequests, 61 SyntacticMatches, 3 SemanticMatches, 42 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 362 ImplicationChecksByTransitivity, 1.0s TimeCoverageRelationStatistics Valid=159, Invalid=1733, Unknown=0, NotChecked=0, Total=1892 [2023-03-31 23:07:00,405 INFO L413 NwaCegarLoop]: 24 mSDtfsCounter, 15 mSDsluCounter, 192 mSDsCounter, 0 mSdLazyCounter, 201 mSolverCounterSat, 2 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.1s Time, 0 mProtectedPredicate, 0 mProtectedAction, 16 SdHoareTripleChecker+Valid, 216 SdHoareTripleChecker+Invalid, 203 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 2 IncrementalHoareTripleChecker+Valid, 201 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.1s IncrementalHoareTripleChecker+Time [2023-03-31 23:07:00,405 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [16 Valid, 216 Invalid, 203 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [2 Valid, 201 Invalid, 0 Unknown, 0 Unchecked, 0.1s Time] [2023-03-31 23:07:00,405 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 65 states. [2023-03-31 23:07:00,417 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 65 to 63. [2023-03-31 23:07:00,418 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 63 states, 48 states have (on average 1.375) internal successors, (66), 52 states have internal predecessors, (66), 7 states have call successors, (7), 5 states have call predecessors, (7), 7 states have return successors, (8), 5 states have call predecessors, (8), 5 states have call successors, (8) [2023-03-31 23:07:00,418 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 63 states to 63 states and 81 transitions. [2023-03-31 23:07:00,418 INFO L78 Accepts]: Start accepts. Automaton has 63 states and 81 transitions. Word has length 31 [2023-03-31 23:07:00,418 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:07:00,418 INFO L495 AbstractCegarLoop]: Abstraction has 63 states and 81 transitions. [2023-03-31 23:07:00,418 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 17 states, 17 states have (on average 2.5294117647058822) internal successors, (43), 17 states have internal predecessors, (43), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:07:00,418 INFO L276 IsEmpty]: Start isEmpty. Operand 63 states and 81 transitions. [2023-03-31 23:07:00,419 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 33 [2023-03-31 23:07:00,419 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:07:00,419 INFO L195 NwaCegarLoop]: trace histogram [2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:07:00,426 INFO L552 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (8)] Ended with exit code 0 [2023-03-31 23:07:00,623 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable14,8 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:00,623 INFO L420 AbstractCegarLoop]: === Iteration 16 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:07:00,624 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:07:00,624 INFO L85 PathProgramCache]: Analyzing trace with hash -1875464900, now seen corresponding path program 6 times [2023-03-31 23:07:00,624 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:07:00,624 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1214002805] [2023-03-31 23:07:00,624 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:07:00,624 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:07:00,646 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:00,728 INFO L134 CoverageAnalysis]: Checked inductivity of 10 backedges. 0 proven. 4 refuted. 0 times theorem prover too weak. 6 trivial. 0 not checked. [2023-03-31 23:07:00,728 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:07:00,728 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1214002805] [2023-03-31 23:07:00,729 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1214002805] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:07:00,729 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [317000] [2023-03-31 23:07:00,729 INFO L93 rtionOrderModulation]: Changing assertion order to TERMS_WITH_SMALL_CONSTANTS_FIRST [2023-03-31 23:07:00,729 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:00,729 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:07:00,730 INFO L229 MonitoredProcess]: Starting monitored process 9 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:07:00,757 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (9)] Waiting until timeout for monitored process [2023-03-31 23:07:00,788 INFO L228 tOrderPrioritization]: Assert order TERMS_WITH_SMALL_CONSTANTS_FIRST issued 0 check-sat command(s) [2023-03-31 23:07:00,789 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2023-03-31 23:07:00,789 INFO L262 TraceCheckSpWp]: Trace formula consists of 130 conjuncts, 14 conjunts are in the unsatisfiable core [2023-03-31 23:07:00,790 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:07:00,886 INFO L134 CoverageAnalysis]: Checked inductivity of 10 backedges. 0 proven. 4 refuted. 0 times theorem prover too weak. 6 trivial. 0 not checked. [2023-03-31 23:07:00,887 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-03-31 23:07:01,037 INFO L134 CoverageAnalysis]: Checked inductivity of 10 backedges. 2 proven. 2 refuted. 0 times theorem prover too weak. 6 trivial. 0 not checked. [2023-03-31 23:07:01,037 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [317000] provided 0 perfect and 2 imperfect interpolant sequences [2023-03-31 23:07:01,037 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [645006530] [2023-03-31 23:07:01,038 INFO L159 IcfgInterpreter]: Started Sifa with 25 locations of interest [2023-03-31 23:07:01,038 INFO L166 IcfgInterpreter]: Building call graph [2023-03-31 23:07:01,038 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2023-03-31 23:07:01,039 INFO L176 IcfgInterpreter]: Starting interpretation [2023-03-31 23:07:01,039 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2023-03-31 23:07:01,050 INFO L197 IcfgInterpreter]: Interpreting procedure main with input of size 8 for LOIs [2023-03-31 23:07:01,119 INFO L197 IcfgInterpreter]: Interpreting procedure __VERIFIER_assert with input of size 26 for LOIs [2023-03-31 23:07:01,126 INFO L197 IcfgInterpreter]: Interpreting procedure student_version with input of size 19 for LOIs [2023-03-31 23:07:01,158 INFO L197 IcfgInterpreter]: Interpreting procedure correct_version with input of size 19 for LOIs [2023-03-31 23:07:01,188 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.init with input of size 7 for LOIs [2023-03-31 23:07:01,190 INFO L180 IcfgInterpreter]: Interpretation finished [2023-03-31 23:07:02,124 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '3955#(and (= |__VERIFIER_assert_#in~cond| 0) (= __VERIFIER_assert_~cond 0) (= |#NULL.offset| 0) (<= 0 |#StackHeapBarrier|) (= |#NULL.base| 0))' at error location [2023-03-31 23:07:02,124 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2023-03-31 23:07:02,124 INFO L185 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2023-03-31 23:07:02,124 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [9, 9, 9] total 17 [2023-03-31 23:07:02,124 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1702850837] [2023-03-31 23:07:02,124 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2023-03-31 23:07:02,124 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 17 states [2023-03-31 23:07:02,125 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:07:02,125 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 17 interpolants. [2023-03-31 23:07:02,125 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=129, Invalid=1353, Unknown=0, NotChecked=0, Total=1482 [2023-03-31 23:07:02,125 INFO L87 Difference]: Start difference. First operand 63 states and 81 transitions. Second operand has 17 states, 17 states have (on average 2.0588235294117645) internal successors, (35), 17 states have internal predecessors, (35), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:07:02,311 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:07:02,311 INFO L93 Difference]: Finished difference Result 79 states and 99 transitions. [2023-03-31 23:07:02,312 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 10 states. [2023-03-31 23:07:02,312 INFO L78 Accepts]: Start accepts. Automaton has has 17 states, 17 states have (on average 2.0588235294117645) internal successors, (35), 17 states have internal predecessors, (35), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) Word has length 32 [2023-03-31 23:07:02,312 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:07:02,312 INFO L225 Difference]: With dead ends: 79 [2023-03-31 23:07:02,313 INFO L226 Difference]: Without dead ends: 68 [2023-03-31 23:07:02,313 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 109 GetRequests, 64 SyntacticMatches, 3 SemanticMatches, 42 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 359 ImplicationChecksByTransitivity, 1.1s TimeCoverageRelationStatistics Valid=158, Invalid=1734, Unknown=0, NotChecked=0, Total=1892 [2023-03-31 23:07:02,314 INFO L413 NwaCegarLoop]: 23 mSDtfsCounter, 20 mSDsluCounter, 245 mSDsCounter, 0 mSdLazyCounter, 274 mSolverCounterSat, 2 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.1s Time, 0 mProtectedPredicate, 0 mProtectedAction, 21 SdHoareTripleChecker+Valid, 268 SdHoareTripleChecker+Invalid, 276 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 2 IncrementalHoareTripleChecker+Valid, 274 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.1s IncrementalHoareTripleChecker+Time [2023-03-31 23:07:02,314 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [21 Valid, 268 Invalid, 276 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [2 Valid, 274 Invalid, 0 Unknown, 0 Unchecked, 0.1s Time] [2023-03-31 23:07:02,314 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 68 states. [2023-03-31 23:07:02,320 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 68 to 65. [2023-03-31 23:07:02,322 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 65 states, 47 states have (on average 1.3617021276595744) internal successors, (64), 53 states have internal predecessors, (64), 8 states have call successors, (8), 5 states have call predecessors, (8), 9 states have return successors, (11), 6 states have call predecessors, (11), 6 states have call successors, (11) [2023-03-31 23:07:02,322 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 65 states to 65 states and 83 transitions. [2023-03-31 23:07:02,322 INFO L78 Accepts]: Start accepts. Automaton has 65 states and 83 transitions. Word has length 32 [2023-03-31 23:07:02,322 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:07:02,322 INFO L495 AbstractCegarLoop]: Abstraction has 65 states and 83 transitions. [2023-03-31 23:07:02,323 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 17 states, 17 states have (on average 2.0588235294117645) internal successors, (35), 17 states have internal predecessors, (35), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:07:02,323 INFO L276 IsEmpty]: Start isEmpty. Operand 65 states and 83 transitions. [2023-03-31 23:07:02,323 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 33 [2023-03-31 23:07:02,323 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:07:02,323 INFO L195 NwaCegarLoop]: trace histogram [2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:07:02,328 INFO L552 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (9)] Ended with exit code 0 [2023-03-31 23:07:02,527 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: 9 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true,SelfDestructingSolverStorable15 [2023-03-31 23:07:02,528 INFO L420 AbstractCegarLoop]: === Iteration 17 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:07:02,528 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:07:02,528 INFO L85 PathProgramCache]: Analyzing trace with hash -41056403, now seen corresponding path program 7 times [2023-03-31 23:07:02,528 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:07:02,528 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1757897526] [2023-03-31 23:07:02,528 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:07:02,529 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:07:02,536 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:02,771 INFO L134 CoverageAnalysis]: Checked inductivity of 10 backedges. 0 proven. 8 refuted. 0 times theorem prover too weak. 2 trivial. 0 not checked. [2023-03-31 23:07:02,771 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:07:02,771 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1757897526] [2023-03-31 23:07:02,771 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1757897526] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:07:02,771 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1694346190] [2023-03-31 23:07:02,771 INFO L93 rtionOrderModulation]: Changing assertion order to NOT_INCREMENTALLY [2023-03-31 23:07:02,771 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:02,771 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:07:02,772 INFO L229 MonitoredProcess]: Starting monitored process 10 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:07:02,780 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (10)] Waiting until timeout for monitored process [2023-03-31 23:07:02,821 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:02,822 INFO L262 TraceCheckSpWp]: Trace formula consists of 179 conjuncts, 38 conjunts are in the unsatisfiable core [2023-03-31 23:07:02,823 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:07:02,962 INFO L134 CoverageAnalysis]: Checked inductivity of 10 backedges. 0 proven. 8 refuted. 0 times theorem prover too weak. 2 trivial. 0 not checked. [2023-03-31 23:07:02,963 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-03-31 23:07:03,141 INFO L134 CoverageAnalysis]: Checked inductivity of 10 backedges. 0 proven. 8 refuted. 0 times theorem prover too weak. 2 trivial. 0 not checked. [2023-03-31 23:07:03,141 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1694346190] provided 0 perfect and 2 imperfect interpolant sequences [2023-03-31 23:07:03,141 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [783323710] [2023-03-31 23:07:03,143 INFO L159 IcfgInterpreter]: Started Sifa with 25 locations of interest [2023-03-31 23:07:03,143 INFO L166 IcfgInterpreter]: Building call graph [2023-03-31 23:07:03,143 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2023-03-31 23:07:03,143 INFO L176 IcfgInterpreter]: Starting interpretation [2023-03-31 23:07:03,144 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2023-03-31 23:07:03,157 INFO L197 IcfgInterpreter]: Interpreting procedure main with input of size 8 for LOIs [2023-03-31 23:07:03,251 INFO L197 IcfgInterpreter]: Interpreting procedure __VERIFIER_assert with input of size 26 for LOIs [2023-03-31 23:07:03,257 INFO L197 IcfgInterpreter]: Interpreting procedure student_version with input of size 19 for LOIs [2023-03-31 23:07:03,283 INFO L197 IcfgInterpreter]: Interpreting procedure correct_version with input of size 19 for LOIs [2023-03-31 23:07:03,308 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.init with input of size 7 for LOIs [2023-03-31 23:07:03,310 INFO L180 IcfgInterpreter]: Interpretation finished [2023-03-31 23:07:04,396 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '4446#(and (= |__VERIFIER_assert_#in~cond| 0) (= __VERIFIER_assert_~cond 0) (= |#NULL.offset| 0) (<= 0 |#StackHeapBarrier|) (= |#NULL.base| 0))' at error location [2023-03-31 23:07:04,397 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2023-03-31 23:07:04,397 INFO L185 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2023-03-31 23:07:04,397 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [20, 20, 20] total 26 [2023-03-31 23:07:04,397 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1999229719] [2023-03-31 23:07:04,397 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2023-03-31 23:07:04,397 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 26 states [2023-03-31 23:07:04,397 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:07:04,398 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 26 interpolants. [2023-03-31 23:07:04,398 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=147, Invalid=2109, Unknown=0, NotChecked=0, Total=2256 [2023-03-31 23:07:04,399 INFO L87 Difference]: Start difference. First operand 65 states and 83 transitions. Second operand has 26 states, 21 states have (on average 1.4761904761904763) internal successors, (31), 21 states have internal predecessors, (31), 4 states have call successors, (6), 3 states have call predecessors, (6), 3 states have return successors, (4), 4 states have call predecessors, (4), 2 states have call successors, (4) [2023-03-31 23:07:04,680 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:07:04,680 INFO L93 Difference]: Finished difference Result 97 states and 130 transitions. [2023-03-31 23:07:04,680 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 21 states. [2023-03-31 23:07:04,680 INFO L78 Accepts]: Start accepts. Automaton has has 26 states, 21 states have (on average 1.4761904761904763) internal successors, (31), 21 states have internal predecessors, (31), 4 states have call successors, (6), 3 states have call predecessors, (6), 3 states have return successors, (4), 4 states have call predecessors, (4), 2 states have call successors, (4) Word has length 32 [2023-03-31 23:07:04,680 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:07:04,681 INFO L225 Difference]: With dead ends: 97 [2023-03-31 23:07:04,681 INFO L226 Difference]: Without dead ends: 91 [2023-03-31 23:07:04,682 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 121 GetRequests, 62 SyntacticMatches, 7 SemanticMatches, 52 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 512 ImplicationChecksByTransitivity, 1.5s TimeCoverageRelationStatistics Valid=177, Invalid=2685, Unknown=0, NotChecked=0, Total=2862 [2023-03-31 23:07:04,682 INFO L413 NwaCegarLoop]: 18 mSDtfsCounter, 22 mSDsluCounter, 311 mSDsCounter, 0 mSdLazyCounter, 567 mSolverCounterSat, 1 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.1s Time, 0 mProtectedPredicate, 0 mProtectedAction, 26 SdHoareTripleChecker+Valid, 329 SdHoareTripleChecker+Invalid, 568 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 1 IncrementalHoareTripleChecker+Valid, 567 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.2s IncrementalHoareTripleChecker+Time [2023-03-31 23:07:04,682 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [26 Valid, 329 Invalid, 568 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [1 Valid, 567 Invalid, 0 Unknown, 0 Unchecked, 0.2s Time] [2023-03-31 23:07:04,682 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 91 states. [2023-03-31 23:07:04,690 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 91 to 85. [2023-03-31 23:07:04,690 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 85 states, 61 states have (on average 1.3770491803278688) internal successors, (84), 71 states have internal predecessors, (84), 10 states have call successors, (10), 5 states have call predecessors, (10), 13 states have return successors, (19), 8 states have call predecessors, (19), 8 states have call successors, (19) [2023-03-31 23:07:04,691 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 85 states to 85 states and 113 transitions. [2023-03-31 23:07:04,691 INFO L78 Accepts]: Start accepts. Automaton has 85 states and 113 transitions. Word has length 32 [2023-03-31 23:07:04,691 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:07:04,691 INFO L495 AbstractCegarLoop]: Abstraction has 85 states and 113 transitions. [2023-03-31 23:07:04,691 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 26 states, 21 states have (on average 1.4761904761904763) internal successors, (31), 21 states have internal predecessors, (31), 4 states have call successors, (6), 3 states have call predecessors, (6), 3 states have return successors, (4), 4 states have call predecessors, (4), 2 states have call successors, (4) [2023-03-31 23:07:04,691 INFO L276 IsEmpty]: Start isEmpty. Operand 85 states and 113 transitions. [2023-03-31 23:07:04,692 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 33 [2023-03-31 23:07:04,692 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:07:04,692 INFO L195 NwaCegarLoop]: trace histogram [2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:07:04,698 INFO L552 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (10)] Ended with exit code 0 [2023-03-31 23:07:04,895 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: 10 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true,SelfDestructingSolverStorable16 [2023-03-31 23:07:04,896 INFO L420 AbstractCegarLoop]: === Iteration 18 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:07:04,896 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:07:04,896 INFO L85 PathProgramCache]: Analyzing trace with hash -1433145238, now seen corresponding path program 8 times [2023-03-31 23:07:04,896 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:07:04,896 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [96667462] [2023-03-31 23:07:04,896 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:07:04,896 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:07:04,902 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:04,979 INFO L134 CoverageAnalysis]: Checked inductivity of 10 backedges. 0 proven. 4 refuted. 0 times theorem prover too weak. 6 trivial. 0 not checked. [2023-03-31 23:07:04,979 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:07:04,979 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [96667462] [2023-03-31 23:07:04,979 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [96667462] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:07:04,979 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1759002696] [2023-03-31 23:07:04,979 INFO L93 rtionOrderModulation]: Changing assertion order to OUTSIDE_LOOP_FIRST2 [2023-03-31 23:07:04,979 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:04,980 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:07:04,980 INFO L229 MonitoredProcess]: Starting monitored process 11 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:07:05,010 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (11)] Waiting until timeout for monitored process [2023-03-31 23:07:05,027 INFO L228 tOrderPrioritization]: Assert order OUTSIDE_LOOP_FIRST2 issued 2 check-sat command(s) [2023-03-31 23:07:05,027 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2023-03-31 23:07:05,027 INFO L262 TraceCheckSpWp]: Trace formula consists of 179 conjuncts, 14 conjunts are in the unsatisfiable core [2023-03-31 23:07:05,028 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:07:05,098 INFO L134 CoverageAnalysis]: Checked inductivity of 10 backedges. 0 proven. 4 refuted. 0 times theorem prover too weak. 6 trivial. 0 not checked. [2023-03-31 23:07:05,098 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-03-31 23:07:05,240 INFO L134 CoverageAnalysis]: Checked inductivity of 10 backedges. 2 proven. 2 refuted. 0 times theorem prover too weak. 6 trivial. 0 not checked. [2023-03-31 23:07:05,240 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1759002696] provided 0 perfect and 2 imperfect interpolant sequences [2023-03-31 23:07:05,240 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [1496412296] [2023-03-31 23:07:05,241 INFO L159 IcfgInterpreter]: Started Sifa with 25 locations of interest [2023-03-31 23:07:05,241 INFO L166 IcfgInterpreter]: Building call graph [2023-03-31 23:07:05,242 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2023-03-31 23:07:05,242 INFO L176 IcfgInterpreter]: Starting interpretation [2023-03-31 23:07:05,242 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2023-03-31 23:07:05,256 INFO L197 IcfgInterpreter]: Interpreting procedure main with input of size 8 for LOIs [2023-03-31 23:07:05,342 INFO L197 IcfgInterpreter]: Interpreting procedure __VERIFIER_assert with input of size 26 for LOIs [2023-03-31 23:07:05,350 INFO L197 IcfgInterpreter]: Interpreting procedure student_version with input of size 19 for LOIs [2023-03-31 23:07:05,387 INFO L197 IcfgInterpreter]: Interpreting procedure correct_version with input of size 19 for LOIs [2023-03-31 23:07:05,411 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.init with input of size 7 for LOIs [2023-03-31 23:07:05,413 INFO L180 IcfgInterpreter]: Interpretation finished [2023-03-31 23:07:06,089 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '4995#(and (= |__VERIFIER_assert_#in~cond| 0) (= __VERIFIER_assert_~cond 0) (= |#NULL.offset| 0) (<= 0 |#StackHeapBarrier|) (= |#NULL.base| 0))' at error location [2023-03-31 23:07:06,089 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2023-03-31 23:07:06,089 INFO L185 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2023-03-31 23:07:06,089 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [9, 9, 9] total 17 [2023-03-31 23:07:06,089 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [411958387] [2023-03-31 23:07:06,090 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2023-03-31 23:07:06,090 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 17 states [2023-03-31 23:07:06,090 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:07:06,090 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 17 interpolants. [2023-03-31 23:07:06,091 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=129, Invalid=1353, Unknown=0, NotChecked=0, Total=1482 [2023-03-31 23:07:06,091 INFO L87 Difference]: Start difference. First operand 85 states and 113 transitions. Second operand has 17 states, 17 states have (on average 2.0588235294117645) internal successors, (35), 17 states have internal predecessors, (35), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:07:06,229 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:07:06,229 INFO L93 Difference]: Finished difference Result 94 states and 121 transitions. [2023-03-31 23:07:06,230 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 10 states. [2023-03-31 23:07:06,230 INFO L78 Accepts]: Start accepts. Automaton has has 17 states, 17 states have (on average 2.0588235294117645) internal successors, (35), 17 states have internal predecessors, (35), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) Word has length 32 [2023-03-31 23:07:06,230 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:07:06,230 INFO L225 Difference]: With dead ends: 94 [2023-03-31 23:07:06,231 INFO L226 Difference]: Without dead ends: 85 [2023-03-31 23:07:06,231 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 109 GetRequests, 64 SyntacticMatches, 3 SemanticMatches, 42 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 359 ImplicationChecksByTransitivity, 0.8s TimeCoverageRelationStatistics Valid=158, Invalid=1734, Unknown=0, NotChecked=0, Total=1892 [2023-03-31 23:07:06,234 INFO L413 NwaCegarLoop]: 24 mSDtfsCounter, 25 mSDsluCounter, 169 mSDsCounter, 0 mSdLazyCounter, 192 mSolverCounterSat, 2 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.1s Time, 0 mProtectedPredicate, 0 mProtectedAction, 26 SdHoareTripleChecker+Valid, 193 SdHoareTripleChecker+Invalid, 194 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 2 IncrementalHoareTripleChecker+Valid, 192 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.1s IncrementalHoareTripleChecker+Time [2023-03-31 23:07:06,234 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [26 Valid, 193 Invalid, 194 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [2 Valid, 192 Invalid, 0 Unknown, 0 Unchecked, 0.1s Time] [2023-03-31 23:07:06,235 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 85 states. [2023-03-31 23:07:06,250 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 85 to 83. [2023-03-31 23:07:06,250 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 83 states, 59 states have (on average 1.3728813559322033) internal successors, (81), 69 states have internal predecessors, (81), 10 states have call successors, (10), 5 states have call predecessors, (10), 13 states have return successors, (16), 8 states have call predecessors, (16), 8 states have call successors, (16) [2023-03-31 23:07:06,251 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 83 states to 83 states and 107 transitions. [2023-03-31 23:07:06,251 INFO L78 Accepts]: Start accepts. Automaton has 83 states and 107 transitions. Word has length 32 [2023-03-31 23:07:06,251 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:07:06,251 INFO L495 AbstractCegarLoop]: Abstraction has 83 states and 107 transitions. [2023-03-31 23:07:06,251 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 17 states, 17 states have (on average 2.0588235294117645) internal successors, (35), 17 states have internal predecessors, (35), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:07:06,251 INFO L276 IsEmpty]: Start isEmpty. Operand 83 states and 107 transitions. [2023-03-31 23:07:06,252 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 34 [2023-03-31 23:07:06,252 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:07:06,252 INFO L195 NwaCegarLoop]: trace histogram [3, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:07:06,258 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (11)] Forceful destruction successful, exit code 0 [2023-03-31 23:07:06,457 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: 11 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true,SelfDestructingSolverStorable17 [2023-03-31 23:07:06,457 INFO L420 AbstractCegarLoop]: === Iteration 19 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:07:06,457 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:07:06,457 INFO L85 PathProgramCache]: Analyzing trace with hash -1156163836, now seen corresponding path program 9 times [2023-03-31 23:07:06,457 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:07:06,458 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [241237622] [2023-03-31 23:07:06,458 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:07:06,458 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:07:06,466 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:06,616 INFO L134 CoverageAnalysis]: Checked inductivity of 13 backedges. 0 proven. 9 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:07:06,616 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:07:06,616 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [241237622] [2023-03-31 23:07:06,616 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [241237622] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:07:06,616 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1505265095] [2023-03-31 23:07:06,616 INFO L93 rtionOrderModulation]: Changing assertion order to TERMS_WITH_SMALL_CONSTANTS_FIRST [2023-03-31 23:07:06,616 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:06,617 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:07:06,617 INFO L229 MonitoredProcess]: Starting monitored process 12 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:07:06,619 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (12)] Waiting until timeout for monitored process [2023-03-31 23:07:06,657 INFO L228 tOrderPrioritization]: Assert order TERMS_WITH_SMALL_CONSTANTS_FIRST issued 0 check-sat command(s) [2023-03-31 23:07:06,658 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2023-03-31 23:07:06,658 INFO L262 TraceCheckSpWp]: Trace formula consists of 135 conjuncts, 16 conjunts are in the unsatisfiable core [2023-03-31 23:07:06,659 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:07:06,798 INFO L134 CoverageAnalysis]: Checked inductivity of 13 backedges. 0 proven. 9 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:07:06,798 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-03-31 23:07:07,038 INFO L134 CoverageAnalysis]: Checked inductivity of 13 backedges. 3 proven. 6 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:07:07,038 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1505265095] provided 0 perfect and 2 imperfect interpolant sequences [2023-03-31 23:07:07,038 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [736750206] [2023-03-31 23:07:07,042 INFO L159 IcfgInterpreter]: Started Sifa with 25 locations of interest [2023-03-31 23:07:07,042 INFO L166 IcfgInterpreter]: Building call graph [2023-03-31 23:07:07,042 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2023-03-31 23:07:07,042 INFO L176 IcfgInterpreter]: Starting interpretation [2023-03-31 23:07:07,043 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2023-03-31 23:07:07,052 INFO L197 IcfgInterpreter]: Interpreting procedure main with input of size 8 for LOIs [2023-03-31 23:07:07,124 INFO L197 IcfgInterpreter]: Interpreting procedure __VERIFIER_assert with input of size 26 for LOIs [2023-03-31 23:07:07,131 INFO L197 IcfgInterpreter]: Interpreting procedure student_version with input of size 19 for LOIs [2023-03-31 23:07:07,159 INFO L197 IcfgInterpreter]: Interpreting procedure correct_version with input of size 19 for LOIs [2023-03-31 23:07:07,187 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.init with input of size 7 for LOIs [2023-03-31 23:07:07,190 INFO L180 IcfgInterpreter]: Interpretation finished [2023-03-31 23:07:08,229 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '5545#(and (= |__VERIFIER_assert_#in~cond| 0) (= __VERIFIER_assert_~cond 0) (= |#NULL.offset| 0) (<= 0 |#StackHeapBarrier|) (= |#NULL.base| 0))' at error location [2023-03-31 23:07:08,229 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2023-03-31 23:07:08,229 INFO L185 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2023-03-31 23:07:08,229 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [11, 11, 11] total 23 [2023-03-31 23:07:08,229 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1276759223] [2023-03-31 23:07:08,230 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2023-03-31 23:07:08,230 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 23 states [2023-03-31 23:07:08,230 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:07:08,230 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 23 interpolants. [2023-03-31 23:07:08,231 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=150, Invalid=1830, Unknown=0, NotChecked=0, Total=1980 [2023-03-31 23:07:08,231 INFO L87 Difference]: Start difference. First operand 83 states and 107 transitions. Second operand has 23 states, 23 states have (on average 2.130434782608696) internal successors, (49), 23 states have internal predecessors, (49), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:07:08,562 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:07:08,562 INFO L93 Difference]: Finished difference Result 97 states and 126 transitions. [2023-03-31 23:07:08,563 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 14 states. [2023-03-31 23:07:08,563 INFO L78 Accepts]: Start accepts. Automaton has has 23 states, 23 states have (on average 2.130434782608696) internal successors, (49), 23 states have internal predecessors, (49), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) Word has length 33 [2023-03-31 23:07:08,563 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:07:08,564 INFO L225 Difference]: With dead ends: 97 [2023-03-31 23:07:08,564 INFO L226 Difference]: Without dead ends: 86 [2023-03-31 23:07:08,565 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 118 GetRequests, 63 SyntacticMatches, 3 SemanticMatches, 52 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 605 ImplicationChecksByTransitivity, 1.4s TimeCoverageRelationStatistics Valid=211, Invalid=2651, Unknown=0, NotChecked=0, Total=2862 [2023-03-31 23:07:08,565 INFO L413 NwaCegarLoop]: 21 mSDtfsCounter, 26 mSDsluCounter, 264 mSDsCounter, 0 mSdLazyCounter, 447 mSolverCounterSat, 5 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.1s Time, 0 mProtectedPredicate, 0 mProtectedAction, 28 SdHoareTripleChecker+Valid, 285 SdHoareTripleChecker+Invalid, 452 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 5 IncrementalHoareTripleChecker+Valid, 447 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.2s IncrementalHoareTripleChecker+Time [2023-03-31 23:07:08,565 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [28 Valid, 285 Invalid, 452 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [5 Valid, 447 Invalid, 0 Unknown, 0 Unchecked, 0.2s Time] [2023-03-31 23:07:08,566 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 86 states. [2023-03-31 23:07:08,575 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 86 to 80. [2023-03-31 23:07:08,576 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 80 states, 56 states have (on average 1.3928571428571428) internal successors, (78), 66 states have internal predecessors, (78), 10 states have call successors, (10), 5 states have call predecessors, (10), 13 states have return successors, (17), 8 states have call predecessors, (17), 8 states have call successors, (17) [2023-03-31 23:07:08,576 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 80 states to 80 states and 105 transitions. [2023-03-31 23:07:08,576 INFO L78 Accepts]: Start accepts. Automaton has 80 states and 105 transitions. Word has length 33 [2023-03-31 23:07:08,576 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:07:08,576 INFO L495 AbstractCegarLoop]: Abstraction has 80 states and 105 transitions. [2023-03-31 23:07:08,576 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 23 states, 23 states have (on average 2.130434782608696) internal successors, (49), 23 states have internal predecessors, (49), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:07:08,576 INFO L276 IsEmpty]: Start isEmpty. Operand 80 states and 105 transitions. [2023-03-31 23:07:08,577 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 34 [2023-03-31 23:07:08,577 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:07:08,577 INFO L195 NwaCegarLoop]: trace histogram [3, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:07:08,592 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (12)] Forceful destruction successful, exit code 0 [2023-03-31 23:07:08,781 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable18,12 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:08,781 INFO L420 AbstractCegarLoop]: === Iteration 20 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:07:08,782 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:07:08,782 INFO L85 PathProgramCache]: Analyzing trace with hash -515732363, now seen corresponding path program 10 times [2023-03-31 23:07:08,782 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:07:08,782 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1581010900] [2023-03-31 23:07:08,782 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:07:08,782 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:07:08,791 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:08,890 INFO L134 CoverageAnalysis]: Checked inductivity of 13 backedges. 0 proven. 9 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:07:08,891 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:07:08,891 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1581010900] [2023-03-31 23:07:08,891 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1581010900] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:07:08,891 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1597584360] [2023-03-31 23:07:08,891 INFO L93 rtionOrderModulation]: Changing assertion order to NOT_INCREMENTALLY [2023-03-31 23:07:08,891 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:08,891 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:07:08,902 INFO L229 MonitoredProcess]: Starting monitored process 13 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:07:08,943 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (13)] Waiting until timeout for monitored process [2023-03-31 23:07:08,961 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:08,962 INFO L262 TraceCheckSpWp]: Trace formula consists of 184 conjuncts, 16 conjunts are in the unsatisfiable core [2023-03-31 23:07:08,962 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:07:09,083 INFO L134 CoverageAnalysis]: Checked inductivity of 13 backedges. 0 proven. 9 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:07:09,083 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-03-31 23:07:09,312 INFO L134 CoverageAnalysis]: Checked inductivity of 13 backedges. 3 proven. 6 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:07:09,312 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1597584360] provided 0 perfect and 2 imperfect interpolant sequences [2023-03-31 23:07:09,313 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [1435114130] [2023-03-31 23:07:09,329 INFO L159 IcfgInterpreter]: Started Sifa with 25 locations of interest [2023-03-31 23:07:09,329 INFO L166 IcfgInterpreter]: Building call graph [2023-03-31 23:07:09,329 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2023-03-31 23:07:09,329 INFO L176 IcfgInterpreter]: Starting interpretation [2023-03-31 23:07:09,329 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2023-03-31 23:07:09,339 INFO L197 IcfgInterpreter]: Interpreting procedure main with input of size 8 for LOIs [2023-03-31 23:07:09,429 INFO L197 IcfgInterpreter]: Interpreting procedure __VERIFIER_assert with input of size 26 for LOIs [2023-03-31 23:07:09,436 INFO L197 IcfgInterpreter]: Interpreting procedure student_version with input of size 19 for LOIs [2023-03-31 23:07:09,463 INFO L197 IcfgInterpreter]: Interpreting procedure correct_version with input of size 19 for LOIs [2023-03-31 23:07:09,489 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.init with input of size 7 for LOIs [2023-03-31 23:07:09,491 INFO L180 IcfgInterpreter]: Interpretation finished [2023-03-31 23:07:10,512 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '6101#(and (= |__VERIFIER_assert_#in~cond| 0) (= __VERIFIER_assert_~cond 0) (= |#NULL.offset| 0) (<= 0 |#StackHeapBarrier|) (= |#NULL.base| 0))' at error location [2023-03-31 23:07:10,512 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2023-03-31 23:07:10,512 INFO L185 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2023-03-31 23:07:10,512 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [11, 11, 11] total 23 [2023-03-31 23:07:10,512 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1380785186] [2023-03-31 23:07:10,512 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2023-03-31 23:07:10,513 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 23 states [2023-03-31 23:07:10,513 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:07:10,513 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 23 interpolants. [2023-03-31 23:07:10,513 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=150, Invalid=1830, Unknown=0, NotChecked=0, Total=1980 [2023-03-31 23:07:10,514 INFO L87 Difference]: Start difference. First operand 80 states and 105 transitions. Second operand has 23 states, 23 states have (on average 2.130434782608696) internal successors, (49), 23 states have internal predecessors, (49), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:07:10,850 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:07:10,850 INFO L93 Difference]: Finished difference Result 92 states and 117 transitions. [2023-03-31 23:07:10,850 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 14 states. [2023-03-31 23:07:10,851 INFO L78 Accepts]: Start accepts. Automaton has has 23 states, 23 states have (on average 2.130434782608696) internal successors, (49), 23 states have internal predecessors, (49), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) Word has length 33 [2023-03-31 23:07:10,851 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:07:10,851 INFO L225 Difference]: With dead ends: 92 [2023-03-31 23:07:10,851 INFO L226 Difference]: Without dead ends: 83 [2023-03-31 23:07:10,852 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 118 GetRequests, 63 SyntacticMatches, 3 SemanticMatches, 52 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 605 ImplicationChecksByTransitivity, 1.4s TimeCoverageRelationStatistics Valid=211, Invalid=2651, Unknown=0, NotChecked=0, Total=2862 [2023-03-31 23:07:10,852 INFO L413 NwaCegarLoop]: 26 mSDtfsCounter, 29 mSDsluCounter, 305 mSDsCounter, 0 mSdLazyCounter, 412 mSolverCounterSat, 5 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.1s Time, 0 mProtectedPredicate, 0 mProtectedAction, 30 SdHoareTripleChecker+Valid, 331 SdHoareTripleChecker+Invalid, 417 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 5 IncrementalHoareTripleChecker+Valid, 412 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.2s IncrementalHoareTripleChecker+Time [2023-03-31 23:07:10,853 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [30 Valid, 331 Invalid, 417 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [5 Valid, 412 Invalid, 0 Unknown, 0 Unchecked, 0.2s Time] [2023-03-31 23:07:10,853 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 83 states. [2023-03-31 23:07:10,863 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 83 to 81. [2023-03-31 23:07:10,864 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 81 states, 57 states have (on average 1.3859649122807018) internal successors, (79), 67 states have internal predecessors, (79), 10 states have call successors, (10), 5 states have call predecessors, (10), 13 states have return successors, (15), 8 states have call predecessors, (15), 8 states have call successors, (15) [2023-03-31 23:07:10,864 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 81 states to 81 states and 104 transitions. [2023-03-31 23:07:10,864 INFO L78 Accepts]: Start accepts. Automaton has 81 states and 104 transitions. Word has length 33 [2023-03-31 23:07:10,864 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:07:10,864 INFO L495 AbstractCegarLoop]: Abstraction has 81 states and 104 transitions. [2023-03-31 23:07:10,865 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 23 states, 23 states have (on average 2.130434782608696) internal successors, (49), 23 states have internal predecessors, (49), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:07:10,865 INFO L276 IsEmpty]: Start isEmpty. Operand 81 states and 104 transitions. [2023-03-31 23:07:10,865 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 34 [2023-03-31 23:07:10,865 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:07:10,865 INFO L195 NwaCegarLoop]: trace histogram [2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:07:10,872 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (13)] Forceful destruction successful, exit code 0 [2023-03-31 23:07:11,070 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable19,13 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:11,070 INFO L420 AbstractCegarLoop]: === Iteration 21 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:07:11,070 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:07:11,071 INFO L85 PathProgramCache]: Analyzing trace with hash -1675694073, now seen corresponding path program 11 times [2023-03-31 23:07:11,071 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:07:11,071 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [875981182] [2023-03-31 23:07:11,071 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:07:11,071 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:07:11,076 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:11,109 INFO L134 CoverageAnalysis]: Checked inductivity of 12 backedges. 1 proven. 3 refuted. 0 times theorem prover too weak. 8 trivial. 0 not checked. [2023-03-31 23:07:11,109 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:07:11,109 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [875981182] [2023-03-31 23:07:11,109 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [875981182] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:07:11,110 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1529680559] [2023-03-31 23:07:11,110 INFO L93 rtionOrderModulation]: Changing assertion order to OUTSIDE_LOOP_FIRST2 [2023-03-31 23:07:11,110 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:11,110 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:07:11,125 INFO L229 MonitoredProcess]: Starting monitored process 14 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:07:11,135 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (14)] Waiting until timeout for monitored process [2023-03-31 23:07:11,180 INFO L228 tOrderPrioritization]: Assert order OUTSIDE_LOOP_FIRST2 issued 2 check-sat command(s) [2023-03-31 23:07:11,180 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2023-03-31 23:07:11,181 INFO L262 TraceCheckSpWp]: Trace formula consists of 184 conjuncts, 6 conjunts are in the unsatisfiable core [2023-03-31 23:07:11,182 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:07:11,208 INFO L134 CoverageAnalysis]: Checked inductivity of 12 backedges. 3 proven. 1 refuted. 0 times theorem prover too weak. 8 trivial. 0 not checked. [2023-03-31 23:07:11,208 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-03-31 23:07:11,239 INFO L134 CoverageAnalysis]: Checked inductivity of 12 backedges. 3 proven. 1 refuted. 0 times theorem prover too weak. 8 trivial. 0 not checked. [2023-03-31 23:07:11,239 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1529680559] provided 0 perfect and 2 imperfect interpolant sequences [2023-03-31 23:07:11,239 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [736709455] [2023-03-31 23:07:11,240 INFO L159 IcfgInterpreter]: Started Sifa with 25 locations of interest [2023-03-31 23:07:11,240 INFO L166 IcfgInterpreter]: Building call graph [2023-03-31 23:07:11,240 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2023-03-31 23:07:11,241 INFO L176 IcfgInterpreter]: Starting interpretation [2023-03-31 23:07:11,241 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2023-03-31 23:07:11,253 INFO L197 IcfgInterpreter]: Interpreting procedure main with input of size 8 for LOIs [2023-03-31 23:07:11,309 INFO L197 IcfgInterpreter]: Interpreting procedure __VERIFIER_assert with input of size 26 for LOIs [2023-03-31 23:07:11,315 INFO L197 IcfgInterpreter]: Interpreting procedure student_version with input of size 19 for LOIs [2023-03-31 23:07:11,341 INFO L197 IcfgInterpreter]: Interpreting procedure correct_version with input of size 19 for LOIs [2023-03-31 23:07:11,366 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.init with input of size 7 for LOIs [2023-03-31 23:07:11,368 INFO L180 IcfgInterpreter]: Interpretation finished [2023-03-31 23:07:12,105 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '6639#(and (= |__VERIFIER_assert_#in~cond| 0) (= __VERIFIER_assert_~cond 0) (= |#NULL.offset| 0) (<= 0 |#StackHeapBarrier|) (= |#NULL.base| 0))' at error location [2023-03-31 23:07:12,106 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2023-03-31 23:07:12,106 INFO L185 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2023-03-31 23:07:12,106 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [7, 7, 7] total 11 [2023-03-31 23:07:12,106 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1660886893] [2023-03-31 23:07:12,106 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2023-03-31 23:07:12,106 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 11 states [2023-03-31 23:07:12,106 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:07:12,107 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 11 interpolants. [2023-03-31 23:07:12,107 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=129, Invalid=927, Unknown=0, NotChecked=0, Total=1056 [2023-03-31 23:07:12,107 INFO L87 Difference]: Start difference. First operand 81 states and 104 transitions. Second operand has 11 states, 11 states have (on average 3.3636363636363638) internal successors, (37), 11 states have internal predecessors, (37), 2 states have call successors, (6), 2 states have call predecessors, (6), 2 states have return successors, (4), 2 states have call predecessors, (4), 2 states have call successors, (4) [2023-03-31 23:07:12,155 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:07:12,155 INFO L93 Difference]: Finished difference Result 119 states and 148 transitions. [2023-03-31 23:07:12,155 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 8 states. [2023-03-31 23:07:12,155 INFO L78 Accepts]: Start accepts. Automaton has has 11 states, 11 states have (on average 3.3636363636363638) internal successors, (37), 11 states have internal predecessors, (37), 2 states have call successors, (6), 2 states have call predecessors, (6), 2 states have return successors, (4), 2 states have call predecessors, (4), 2 states have call successors, (4) Word has length 33 [2023-03-31 23:07:12,155 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:07:12,156 INFO L225 Difference]: With dead ends: 119 [2023-03-31 23:07:12,156 INFO L226 Difference]: Without dead ends: 76 [2023-03-31 23:07:12,156 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 106 GetRequests, 70 SyntacticMatches, 4 SemanticMatches, 32 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 381 ImplicationChecksByTransitivity, 0.8s TimeCoverageRelationStatistics Valid=137, Invalid=985, Unknown=0, NotChecked=0, Total=1122 [2023-03-31 23:07:12,157 INFO L413 NwaCegarLoop]: 23 mSDtfsCounter, 9 mSDsluCounter, 107 mSDsCounter, 0 mSdLazyCounter, 68 mSolverCounterSat, 1 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.0s Time, 0 mProtectedPredicate, 0 mProtectedAction, 9 SdHoareTripleChecker+Valid, 130 SdHoareTripleChecker+Invalid, 69 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 1 IncrementalHoareTripleChecker+Valid, 68 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.0s IncrementalHoareTripleChecker+Time [2023-03-31 23:07:12,157 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [9 Valid, 130 Invalid, 69 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [1 Valid, 68 Invalid, 0 Unknown, 0 Unchecked, 0.0s Time] [2023-03-31 23:07:12,157 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 76 states. [2023-03-31 23:07:12,167 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 76 to 72. [2023-03-31 23:07:12,168 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 72 states, 54 states have (on average 1.3333333333333333) internal successors, (72), 60 states have internal predecessors, (72), 8 states have call successors, (8), 5 states have call predecessors, (8), 9 states have return successors, (9), 6 states have call predecessors, (9), 6 states have call successors, (9) [2023-03-31 23:07:12,169 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 72 states to 72 states and 89 transitions. [2023-03-31 23:07:12,169 INFO L78 Accepts]: Start accepts. Automaton has 72 states and 89 transitions. Word has length 33 [2023-03-31 23:07:12,169 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:07:12,169 INFO L495 AbstractCegarLoop]: Abstraction has 72 states and 89 transitions. [2023-03-31 23:07:12,169 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 11 states, 11 states have (on average 3.3636363636363638) internal successors, (37), 11 states have internal predecessors, (37), 2 states have call successors, (6), 2 states have call predecessors, (6), 2 states have return successors, (4), 2 states have call predecessors, (4), 2 states have call successors, (4) [2023-03-31 23:07:12,169 INFO L276 IsEmpty]: Start isEmpty. Operand 72 states and 89 transitions. [2023-03-31 23:07:12,170 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 34 [2023-03-31 23:07:12,170 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:07:12,170 INFO L195 NwaCegarLoop]: trace histogram [2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:07:12,175 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (14)] Forceful destruction successful, exit code 0 [2023-03-31 23:07:12,375 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: 14 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true,SelfDestructingSolverStorable20 [2023-03-31 23:07:12,375 INFO L420 AbstractCegarLoop]: === Iteration 22 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:07:12,375 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:07:12,375 INFO L85 PathProgramCache]: Analyzing trace with hash 587187518, now seen corresponding path program 12 times [2023-03-31 23:07:12,375 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:07:12,375 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [168524128] [2023-03-31 23:07:12,376 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:07:12,376 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:07:12,382 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:12,417 INFO L134 CoverageAnalysis]: Checked inductivity of 12 backedges. 1 proven. 3 refuted. 0 times theorem prover too weak. 8 trivial. 0 not checked. [2023-03-31 23:07:12,418 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:07:12,418 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [168524128] [2023-03-31 23:07:12,418 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [168524128] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:07:12,418 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [2015764272] [2023-03-31 23:07:12,418 INFO L93 rtionOrderModulation]: Changing assertion order to TERMS_WITH_SMALL_CONSTANTS_FIRST [2023-03-31 23:07:12,418 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:12,418 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:07:12,433 INFO L229 MonitoredProcess]: Starting monitored process 15 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:07:12,434 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (15)] Waiting until timeout for monitored process [2023-03-31 23:07:12,477 INFO L228 tOrderPrioritization]: Assert order TERMS_WITH_SMALL_CONSTANTS_FIRST issued 0 check-sat command(s) [2023-03-31 23:07:12,478 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2023-03-31 23:07:12,478 INFO L262 TraceCheckSpWp]: Trace formula consists of 135 conjuncts, 6 conjunts are in the unsatisfiable core [2023-03-31 23:07:12,479 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:07:12,502 INFO L134 CoverageAnalysis]: Checked inductivity of 12 backedges. 3 proven. 1 refuted. 0 times theorem prover too weak. 8 trivial. 0 not checked. [2023-03-31 23:07:12,502 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-03-31 23:07:12,531 INFO L134 CoverageAnalysis]: Checked inductivity of 12 backedges. 3 proven. 1 refuted. 0 times theorem prover too weak. 8 trivial. 0 not checked. [2023-03-31 23:07:12,531 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [2015764272] provided 0 perfect and 2 imperfect interpolant sequences [2023-03-31 23:07:12,531 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [509426174] [2023-03-31 23:07:12,532 INFO L159 IcfgInterpreter]: Started Sifa with 25 locations of interest [2023-03-31 23:07:12,532 INFO L166 IcfgInterpreter]: Building call graph [2023-03-31 23:07:12,533 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2023-03-31 23:07:12,533 INFO L176 IcfgInterpreter]: Starting interpretation [2023-03-31 23:07:12,533 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2023-03-31 23:07:12,541 INFO L197 IcfgInterpreter]: Interpreting procedure main with input of size 8 for LOIs [2023-03-31 23:07:12,598 INFO L197 IcfgInterpreter]: Interpreting procedure __VERIFIER_assert with input of size 26 for LOIs [2023-03-31 23:07:12,604 INFO L197 IcfgInterpreter]: Interpreting procedure student_version with input of size 19 for LOIs [2023-03-31 23:07:12,630 INFO L197 IcfgInterpreter]: Interpreting procedure correct_version with input of size 19 for LOIs [2023-03-31 23:07:12,659 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.init with input of size 7 for LOIs [2023-03-31 23:07:12,671 INFO L180 IcfgInterpreter]: Interpretation finished [2023-03-31 23:07:13,246 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '7197#(and (= |__VERIFIER_assert_#in~cond| 0) (= __VERIFIER_assert_~cond 0) (= |#NULL.offset| 0) (<= 0 |#StackHeapBarrier|) (= |#NULL.base| 0))' at error location [2023-03-31 23:07:13,247 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2023-03-31 23:07:13,247 INFO L185 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2023-03-31 23:07:13,247 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [7, 7, 7] total 11 [2023-03-31 23:07:13,247 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1542511148] [2023-03-31 23:07:13,247 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2023-03-31 23:07:13,247 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 11 states [2023-03-31 23:07:13,247 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:07:13,248 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 11 interpolants. [2023-03-31 23:07:13,248 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=129, Invalid=927, Unknown=0, NotChecked=0, Total=1056 [2023-03-31 23:07:13,248 INFO L87 Difference]: Start difference. First operand 72 states and 89 transitions. Second operand has 11 states, 11 states have (on average 2.727272727272727) internal successors, (30), 11 states have internal predecessors, (30), 2 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 2 states have call predecessors, (3), 1 states have call successors, (3) [2023-03-31 23:07:13,284 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:07:13,284 INFO L93 Difference]: Finished difference Result 84 states and 103 transitions. [2023-03-31 23:07:13,285 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 8 states. [2023-03-31 23:07:13,285 INFO L78 Accepts]: Start accepts. Automaton has has 11 states, 11 states have (on average 2.727272727272727) internal successors, (30), 11 states have internal predecessors, (30), 2 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 2 states have call predecessors, (3), 1 states have call successors, (3) Word has length 33 [2023-03-31 23:07:13,285 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:07:13,285 INFO L225 Difference]: With dead ends: 84 [2023-03-31 23:07:13,285 INFO L226 Difference]: Without dead ends: 75 [2023-03-31 23:07:13,286 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 106 GetRequests, 70 SyntacticMatches, 4 SemanticMatches, 32 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 381 ImplicationChecksByTransitivity, 0.6s TimeCoverageRelationStatistics Valid=137, Invalid=985, Unknown=0, NotChecked=0, Total=1122 [2023-03-31 23:07:13,287 INFO L413 NwaCegarLoop]: 22 mSDtfsCounter, 19 mSDsluCounter, 85 mSDsCounter, 0 mSdLazyCounter, 68 mSolverCounterSat, 1 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.0s Time, 0 mProtectedPredicate, 0 mProtectedAction, 19 SdHoareTripleChecker+Valid, 107 SdHoareTripleChecker+Invalid, 69 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 1 IncrementalHoareTripleChecker+Valid, 68 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.0s IncrementalHoareTripleChecker+Time [2023-03-31 23:07:13,288 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [19 Valid, 107 Invalid, 69 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [1 Valid, 68 Invalid, 0 Unknown, 0 Unchecked, 0.0s Time] [2023-03-31 23:07:13,288 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 75 states. [2023-03-31 23:07:13,306 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 75 to 75. [2023-03-31 23:07:13,306 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 75 states, 57 states have (on average 1.3157894736842106) internal successors, (75), 63 states have internal predecessors, (75), 8 states have call successors, (8), 5 states have call predecessors, (8), 9 states have return successors, (9), 6 states have call predecessors, (9), 6 states have call successors, (9) [2023-03-31 23:07:13,308 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 75 states to 75 states and 92 transitions. [2023-03-31 23:07:13,308 INFO L78 Accepts]: Start accepts. Automaton has 75 states and 92 transitions. Word has length 33 [2023-03-31 23:07:13,309 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:07:13,309 INFO L495 AbstractCegarLoop]: Abstraction has 75 states and 92 transitions. [2023-03-31 23:07:13,309 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 11 states, 11 states have (on average 2.727272727272727) internal successors, (30), 11 states have internal predecessors, (30), 2 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 2 states have call predecessors, (3), 1 states have call successors, (3) [2023-03-31 23:07:13,309 INFO L276 IsEmpty]: Start isEmpty. Operand 75 states and 92 transitions. [2023-03-31 23:07:13,314 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 35 [2023-03-31 23:07:13,314 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:07:13,314 INFO L195 NwaCegarLoop]: trace histogram [3, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:07:13,334 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (15)] Forceful destruction successful, exit code 0 [2023-03-31 23:07:13,518 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable21,15 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:13,518 INFO L420 AbstractCegarLoop]: === Iteration 23 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:07:13,518 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:07:13,519 INFO L85 PathProgramCache]: Analyzing trace with hash 1308750588, now seen corresponding path program 13 times [2023-03-31 23:07:13,519 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:07:13,519 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [410392193] [2023-03-31 23:07:13,519 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:07:13,519 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:07:13,528 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:13,832 INFO L134 CoverageAnalysis]: Checked inductivity of 16 backedges. 0 proven. 14 refuted. 0 times theorem prover too weak. 2 trivial. 0 not checked. [2023-03-31 23:07:13,832 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:07:13,832 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [410392193] [2023-03-31 23:07:13,832 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [410392193] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:07:13,832 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1346638045] [2023-03-31 23:07:13,832 INFO L93 rtionOrderModulation]: Changing assertion order to NOT_INCREMENTALLY [2023-03-31 23:07:13,833 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:13,833 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:07:13,835 INFO L229 MonitoredProcess]: Starting monitored process 16 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:07:13,835 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (16)] Waiting until timeout for monitored process [2023-03-31 23:07:13,882 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:13,883 INFO L262 TraceCheckSpWp]: Trace formula consists of 189 conjuncts, 42 conjunts are in the unsatisfiable core [2023-03-31 23:07:13,884 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:07:14,003 INFO L134 CoverageAnalysis]: Checked inductivity of 16 backedges. 0 proven. 14 refuted. 0 times theorem prover too weak. 2 trivial. 0 not checked. [2023-03-31 23:07:14,003 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-03-31 23:07:14,147 INFO L134 CoverageAnalysis]: Checked inductivity of 16 backedges. 0 proven. 14 refuted. 0 times theorem prover too weak. 2 trivial. 0 not checked. [2023-03-31 23:07:14,147 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1346638045] provided 0 perfect and 2 imperfect interpolant sequences [2023-03-31 23:07:14,147 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [198044963] [2023-03-31 23:07:14,148 INFO L159 IcfgInterpreter]: Started Sifa with 25 locations of interest [2023-03-31 23:07:14,148 INFO L166 IcfgInterpreter]: Building call graph [2023-03-31 23:07:14,159 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2023-03-31 23:07:14,159 INFO L176 IcfgInterpreter]: Starting interpretation [2023-03-31 23:07:14,159 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2023-03-31 23:07:14,168 INFO L197 IcfgInterpreter]: Interpreting procedure main with input of size 8 for LOIs [2023-03-31 23:07:14,266 INFO L197 IcfgInterpreter]: Interpreting procedure __VERIFIER_assert with input of size 26 for LOIs [2023-03-31 23:07:14,274 INFO L197 IcfgInterpreter]: Interpreting procedure student_version with input of size 19 for LOIs [2023-03-31 23:07:14,305 INFO L197 IcfgInterpreter]: Interpreting procedure correct_version with input of size 19 for LOIs [2023-03-31 23:07:14,330 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.init with input of size 7 for LOIs [2023-03-31 23:07:14,332 INFO L180 IcfgInterpreter]: Interpretation finished [2023-03-31 23:07:15,194 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '7725#(and (= |__VERIFIER_assert_#in~cond| 0) (= __VERIFIER_assert_~cond 0) (= |#NULL.offset| 0) (<= 0 |#StackHeapBarrier|) (= |#NULL.base| 0))' at error location [2023-03-31 23:07:15,194 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2023-03-31 23:07:15,194 INFO L185 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2023-03-31 23:07:15,194 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [22, 22, 22] total 28 [2023-03-31 23:07:15,194 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [946897779] [2023-03-31 23:07:15,194 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2023-03-31 23:07:15,195 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 28 states [2023-03-31 23:07:15,195 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:07:15,195 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 28 interpolants. [2023-03-31 23:07:15,195 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=151, Invalid=2299, Unknown=0, NotChecked=0, Total=2450 [2023-03-31 23:07:15,196 INFO L87 Difference]: Start difference. First operand 75 states and 92 transitions. Second operand has 28 states, 23 states have (on average 1.434782608695652) internal successors, (33), 23 states have internal predecessors, (33), 4 states have call successors, (6), 3 states have call predecessors, (6), 3 states have return successors, (4), 4 states have call predecessors, (4), 2 states have call successors, (4) [2023-03-31 23:07:15,589 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:07:15,589 INFO L93 Difference]: Finished difference Result 103 states and 127 transitions. [2023-03-31 23:07:15,590 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 23 states. [2023-03-31 23:07:15,590 INFO L78 Accepts]: Start accepts. Automaton has has 28 states, 23 states have (on average 1.434782608695652) internal successors, (33), 23 states have internal predecessors, (33), 4 states have call successors, (6), 3 states have call predecessors, (6), 3 states have return successors, (4), 4 states have call predecessors, (4), 2 states have call successors, (4) Word has length 34 [2023-03-31 23:07:15,590 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:07:15,591 INFO L225 Difference]: With dead ends: 103 [2023-03-31 23:07:15,591 INFO L226 Difference]: Without dead ends: 97 [2023-03-31 23:07:15,592 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 129 GetRequests, 68 SyntacticMatches, 7 SemanticMatches, 54 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 513 ImplicationChecksByTransitivity, 1.3s TimeCoverageRelationStatistics Valid=181, Invalid=2899, Unknown=0, NotChecked=0, Total=3080 [2023-03-31 23:07:15,592 INFO L413 NwaCegarLoop]: 23 mSDtfsCounter, 28 mSDsluCounter, 438 mSDsCounter, 0 mSdLazyCounter, 806 mSolverCounterSat, 1 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.2s Time, 0 mProtectedPredicate, 0 mProtectedAction, 32 SdHoareTripleChecker+Valid, 461 SdHoareTripleChecker+Invalid, 807 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 1 IncrementalHoareTripleChecker+Valid, 806 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.3s IncrementalHoareTripleChecker+Time [2023-03-31 23:07:15,592 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [32 Valid, 461 Invalid, 807 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [1 Valid, 806 Invalid, 0 Unknown, 0 Unchecked, 0.3s Time] [2023-03-31 23:07:15,593 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 97 states. [2023-03-31 23:07:15,613 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 97 to 85. [2023-03-31 23:07:15,613 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 85 states, 64 states have (on average 1.3125) internal successors, (84), 72 states have internal predecessors, (84), 9 states have call successors, (9), 5 states have call predecessors, (9), 11 states have return successors, (12), 7 states have call predecessors, (12), 7 states have call successors, (12) [2023-03-31 23:07:15,614 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 85 states to 85 states and 105 transitions. [2023-03-31 23:07:15,614 INFO L78 Accepts]: Start accepts. Automaton has 85 states and 105 transitions. Word has length 34 [2023-03-31 23:07:15,614 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:07:15,614 INFO L495 AbstractCegarLoop]: Abstraction has 85 states and 105 transitions. [2023-03-31 23:07:15,614 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 28 states, 23 states have (on average 1.434782608695652) internal successors, (33), 23 states have internal predecessors, (33), 4 states have call successors, (6), 3 states have call predecessors, (6), 3 states have return successors, (4), 4 states have call predecessors, (4), 2 states have call successors, (4) [2023-03-31 23:07:15,614 INFO L276 IsEmpty]: Start isEmpty. Operand 85 states and 105 transitions. [2023-03-31 23:07:15,615 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 35 [2023-03-31 23:07:15,615 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:07:15,615 INFO L195 NwaCegarLoop]: trace histogram [2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:07:15,623 INFO L552 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (16)] Ended with exit code 0 [2023-03-31 23:07:15,820 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable22,16 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:15,820 INFO L420 AbstractCegarLoop]: === Iteration 24 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:07:15,820 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:07:15,820 INFO L85 PathProgramCache]: Analyzing trace with hash -326306998, now seen corresponding path program 14 times [2023-03-31 23:07:15,820 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:07:15,821 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [259255104] [2023-03-31 23:07:15,821 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:07:15,821 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:07:15,828 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:16,069 INFO L134 CoverageAnalysis]: Checked inductivity of 14 backedges. 0 proven. 8 refuted. 0 times theorem prover too weak. 6 trivial. 0 not checked. [2023-03-31 23:07:16,069 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:07:16,069 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [259255104] [2023-03-31 23:07:16,069 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [259255104] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:07:16,069 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1549258205] [2023-03-31 23:07:16,069 INFO L93 rtionOrderModulation]: Changing assertion order to OUTSIDE_LOOP_FIRST2 [2023-03-31 23:07:16,069 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:16,069 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:07:16,070 INFO L229 MonitoredProcess]: Starting monitored process 17 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:07:16,105 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (17)] Waiting until timeout for monitored process [2023-03-31 23:07:16,149 INFO L228 tOrderPrioritization]: Assert order OUTSIDE_LOOP_FIRST2 issued 2 check-sat command(s) [2023-03-31 23:07:16,149 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2023-03-31 23:07:16,150 INFO L262 TraceCheckSpWp]: Trace formula consists of 189 conjuncts, 38 conjunts are in the unsatisfiable core [2023-03-31 23:07:16,151 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:07:16,325 INFO L134 CoverageAnalysis]: Checked inductivity of 14 backedges. 0 proven. 8 refuted. 0 times theorem prover too weak. 6 trivial. 0 not checked. [2023-03-31 23:07:16,325 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-03-31 23:07:16,474 INFO L134 CoverageAnalysis]: Checked inductivity of 14 backedges. 0 proven. 8 refuted. 0 times theorem prover too weak. 6 trivial. 0 not checked. [2023-03-31 23:07:16,475 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1549258205] provided 0 perfect and 2 imperfect interpolant sequences [2023-03-31 23:07:16,475 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [332399459] [2023-03-31 23:07:16,477 INFO L159 IcfgInterpreter]: Started Sifa with 25 locations of interest [2023-03-31 23:07:16,477 INFO L166 IcfgInterpreter]: Building call graph [2023-03-31 23:07:16,477 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2023-03-31 23:07:16,477 INFO L176 IcfgInterpreter]: Starting interpretation [2023-03-31 23:07:16,477 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2023-03-31 23:07:16,492 INFO L197 IcfgInterpreter]: Interpreting procedure main with input of size 8 for LOIs [2023-03-31 23:07:16,577 INFO L197 IcfgInterpreter]: Interpreting procedure __VERIFIER_assert with input of size 26 for LOIs [2023-03-31 23:07:16,584 INFO L197 IcfgInterpreter]: Interpreting procedure student_version with input of size 19 for LOIs [2023-03-31 23:07:16,612 INFO L197 IcfgInterpreter]: Interpreting procedure correct_version with input of size 19 for LOIs [2023-03-31 23:07:16,638 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.init with input of size 7 for LOIs [2023-03-31 23:07:16,640 INFO L180 IcfgInterpreter]: Interpretation finished [2023-03-31 23:07:17,624 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '8315#(and (= |__VERIFIER_assert_#in~cond| 0) (= __VERIFIER_assert_~cond 0) (= |#NULL.offset| 0) (<= 0 |#StackHeapBarrier|) (= |#NULL.base| 0))' at error location [2023-03-31 23:07:17,624 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2023-03-31 23:07:17,624 INFO L185 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2023-03-31 23:07:17,624 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [20, 20, 20] total 28 [2023-03-31 23:07:17,624 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1361970260] [2023-03-31 23:07:17,624 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2023-03-31 23:07:17,625 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 28 states [2023-03-31 23:07:17,625 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:07:17,625 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 28 interpolants. [2023-03-31 23:07:17,625 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=155, Invalid=2295, Unknown=0, NotChecked=0, Total=2450 [2023-03-31 23:07:17,626 INFO L87 Difference]: Start difference. First operand 85 states and 105 transitions. Second operand has 28 states, 23 states have (on average 1.5217391304347827) internal successors, (35), 23 states have internal predecessors, (35), 4 states have call successors, (6), 3 states have call predecessors, (6), 3 states have return successors, (4), 4 states have call predecessors, (4), 2 states have call successors, (4) [2023-03-31 23:07:17,881 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:07:17,882 INFO L93 Difference]: Finished difference Result 99 states and 122 transitions. [2023-03-31 23:07:17,882 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 21 states. [2023-03-31 23:07:17,882 INFO L78 Accepts]: Start accepts. Automaton has has 28 states, 23 states have (on average 1.5217391304347827) internal successors, (35), 23 states have internal predecessors, (35), 4 states have call successors, (6), 3 states have call predecessors, (6), 3 states have return successors, (4), 4 states have call predecessors, (4), 2 states have call successors, (4) Word has length 34 [2023-03-31 23:07:17,882 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:07:17,883 INFO L225 Difference]: With dead ends: 99 [2023-03-31 23:07:17,883 INFO L226 Difference]: Without dead ends: 93 [2023-03-31 23:07:17,883 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 127 GetRequests, 64 SyntacticMatches, 9 SemanticMatches, 54 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 601 ImplicationChecksByTransitivity, 1.4s TimeCoverageRelationStatistics Valid=185, Invalid=2895, Unknown=0, NotChecked=0, Total=3080 [2023-03-31 23:07:17,884 INFO L413 NwaCegarLoop]: 19 mSDtfsCounter, 16 mSDsluCounter, 348 mSDsCounter, 0 mSdLazyCounter, 504 mSolverCounterSat, 1 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.1s Time, 0 mProtectedPredicate, 0 mProtectedAction, 18 SdHoareTripleChecker+Valid, 367 SdHoareTripleChecker+Invalid, 505 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 1 IncrementalHoareTripleChecker+Valid, 504 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.2s IncrementalHoareTripleChecker+Time [2023-03-31 23:07:17,884 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [18 Valid, 367 Invalid, 505 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [1 Valid, 504 Invalid, 0 Unknown, 0 Unchecked, 0.2s Time] [2023-03-31 23:07:17,884 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 93 states. [2023-03-31 23:07:17,896 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 93 to 91. [2023-03-31 23:07:17,896 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 91 states, 67 states have (on average 1.328358208955224) internal successors, (89), 77 states have internal predecessors, (89), 10 states have call successors, (10), 5 states have call predecessors, (10), 13 states have return successors, (15), 8 states have call predecessors, (15), 8 states have call successors, (15) [2023-03-31 23:07:17,897 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 91 states to 91 states and 114 transitions. [2023-03-31 23:07:17,897 INFO L78 Accepts]: Start accepts. Automaton has 91 states and 114 transitions. Word has length 34 [2023-03-31 23:07:17,897 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:07:17,897 INFO L495 AbstractCegarLoop]: Abstraction has 91 states and 114 transitions. [2023-03-31 23:07:17,897 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 28 states, 23 states have (on average 1.5217391304347827) internal successors, (35), 23 states have internal predecessors, (35), 4 states have call successors, (6), 3 states have call predecessors, (6), 3 states have return successors, (4), 4 states have call predecessors, (4), 2 states have call successors, (4) [2023-03-31 23:07:17,897 INFO L276 IsEmpty]: Start isEmpty. Operand 91 states and 114 transitions. [2023-03-31 23:07:17,898 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 36 [2023-03-31 23:07:17,898 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:07:17,898 INFO L195 NwaCegarLoop]: trace histogram [4, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:07:17,922 INFO L552 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (17)] Ended with exit code 0 [2023-03-31 23:07:18,102 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: 17 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true,SelfDestructingSolverStorable23 [2023-03-31 23:07:18,103 INFO L420 AbstractCegarLoop]: === Iteration 25 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:07:18,103 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:07:18,103 INFO L85 PathProgramCache]: Analyzing trace with hash 2033147221, now seen corresponding path program 15 times [2023-03-31 23:07:18,103 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:07:18,103 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1332118929] [2023-03-31 23:07:18,103 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:07:18,103 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:07:18,113 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:18,313 INFO L134 CoverageAnalysis]: Checked inductivity of 20 backedges. 0 proven. 16 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:07:18,314 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:07:18,314 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1332118929] [2023-03-31 23:07:18,314 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1332118929] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:07:18,314 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [940796395] [2023-03-31 23:07:18,314 INFO L93 rtionOrderModulation]: Changing assertion order to TERMS_WITH_SMALL_CONSTANTS_FIRST [2023-03-31 23:07:18,314 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:18,314 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:07:18,323 INFO L229 MonitoredProcess]: Starting monitored process 18 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:07:18,360 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (18)] Waiting until timeout for monitored process [2023-03-31 23:07:18,380 INFO L228 tOrderPrioritization]: Assert order TERMS_WITH_SMALL_CONSTANTS_FIRST issued 0 check-sat command(s) [2023-03-31 23:07:18,381 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2023-03-31 23:07:18,381 INFO L262 TraceCheckSpWp]: Trace formula consists of 145 conjuncts, 18 conjunts are in the unsatisfiable core [2023-03-31 23:07:18,382 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:07:18,548 INFO L134 CoverageAnalysis]: Checked inductivity of 20 backedges. 0 proven. 16 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:07:18,548 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-03-31 23:07:18,866 INFO L134 CoverageAnalysis]: Checked inductivity of 20 backedges. 4 proven. 12 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:07:18,866 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [940796395] provided 0 perfect and 2 imperfect interpolant sequences [2023-03-31 23:07:18,866 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [2104786819] [2023-03-31 23:07:18,867 INFO L159 IcfgInterpreter]: Started Sifa with 25 locations of interest [2023-03-31 23:07:18,867 INFO L166 IcfgInterpreter]: Building call graph [2023-03-31 23:07:18,867 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2023-03-31 23:07:18,867 INFO L176 IcfgInterpreter]: Starting interpretation [2023-03-31 23:07:18,867 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2023-03-31 23:07:18,876 INFO L197 IcfgInterpreter]: Interpreting procedure main with input of size 8 for LOIs [2023-03-31 23:07:18,934 INFO L197 IcfgInterpreter]: Interpreting procedure __VERIFIER_assert with input of size 26 for LOIs [2023-03-31 23:07:18,940 INFO L197 IcfgInterpreter]: Interpreting procedure student_version with input of size 19 for LOIs [2023-03-31 23:07:18,980 INFO L197 IcfgInterpreter]: Interpreting procedure correct_version with input of size 19 for LOIs [2023-03-31 23:07:19,005 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.init with input of size 7 for LOIs [2023-03-31 23:07:19,007 INFO L180 IcfgInterpreter]: Interpretation finished [2023-03-31 23:07:19,928 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '8912#(and (= |__VERIFIER_assert_#in~cond| 0) (= __VERIFIER_assert_~cond 0) (= |#NULL.offset| 0) (<= 0 |#StackHeapBarrier|) (= |#NULL.base| 0))' at error location [2023-03-31 23:07:19,928 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2023-03-31 23:07:19,928 INFO L185 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2023-03-31 23:07:19,928 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [13, 13, 13] total 29 [2023-03-31 23:07:19,928 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1928963514] [2023-03-31 23:07:19,928 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2023-03-31 23:07:19,931 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 29 states [2023-03-31 23:07:19,931 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:07:19,931 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 29 interpolants. [2023-03-31 23:07:19,932 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=167, Invalid=2383, Unknown=0, NotChecked=0, Total=2550 [2023-03-31 23:07:19,932 INFO L87 Difference]: Start difference. First operand 91 states and 114 transitions. Second operand has 29 states, 29 states have (on average 1.896551724137931) internal successors, (55), 29 states have internal predecessors, (55), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:07:20,475 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:07:20,475 INFO L93 Difference]: Finished difference Result 111 states and 139 transitions. [2023-03-31 23:07:20,475 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 17 states. [2023-03-31 23:07:20,476 INFO L78 Accepts]: Start accepts. Automaton has has 29 states, 29 states have (on average 1.896551724137931) internal successors, (55), 29 states have internal predecessors, (55), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) Word has length 35 [2023-03-31 23:07:20,476 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:07:20,476 INFO L225 Difference]: With dead ends: 111 [2023-03-31 23:07:20,476 INFO L226 Difference]: Without dead ends: 100 [2023-03-31 23:07:20,477 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 127 GetRequests, 65 SyntacticMatches, 3 SemanticMatches, 59 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 645 ImplicationChecksByTransitivity, 1.6s TimeCoverageRelationStatistics Valid=248, Invalid=3412, Unknown=0, NotChecked=0, Total=3660 [2023-03-31 23:07:20,478 INFO L413 NwaCegarLoop]: 23 mSDtfsCounter, 61 mSDsluCounter, 311 mSDsCounter, 0 mSdLazyCounter, 594 mSolverCounterSat, 8 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.2s Time, 0 mProtectedPredicate, 0 mProtectedAction, 64 SdHoareTripleChecker+Valid, 334 SdHoareTripleChecker+Invalid, 602 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 8 IncrementalHoareTripleChecker+Valid, 594 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.2s IncrementalHoareTripleChecker+Time [2023-03-31 23:07:20,478 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [64 Valid, 334 Invalid, 602 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [8 Valid, 594 Invalid, 0 Unknown, 0 Unchecked, 0.2s Time] [2023-03-31 23:07:20,478 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 100 states. [2023-03-31 23:07:20,498 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 100 to 94. [2023-03-31 23:07:20,498 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 94 states, 70 states have (on average 1.3428571428571427) internal successors, (94), 80 states have internal predecessors, (94), 10 states have call successors, (10), 5 states have call predecessors, (10), 13 states have return successors, (15), 8 states have call predecessors, (15), 8 states have call successors, (15) [2023-03-31 23:07:20,499 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 94 states to 94 states and 119 transitions. [2023-03-31 23:07:20,499 INFO L78 Accepts]: Start accepts. Automaton has 94 states and 119 transitions. Word has length 35 [2023-03-31 23:07:20,499 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:07:20,499 INFO L495 AbstractCegarLoop]: Abstraction has 94 states and 119 transitions. [2023-03-31 23:07:20,499 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 29 states, 29 states have (on average 1.896551724137931) internal successors, (55), 29 states have internal predecessors, (55), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:07:20,500 INFO L276 IsEmpty]: Start isEmpty. Operand 94 states and 119 transitions. [2023-03-31 23:07:20,500 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 36 [2023-03-31 23:07:20,500 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:07:20,500 INFO L195 NwaCegarLoop]: trace histogram [4, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:07:20,507 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (18)] Forceful destruction successful, exit code 0 [2023-03-31 23:07:20,701 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable24,18 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:20,701 INFO L420 AbstractCegarLoop]: === Iteration 26 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:07:20,701 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:07:20,701 INFO L85 PathProgramCache]: Analyzing trace with hash 411686404, now seen corresponding path program 16 times [2023-03-31 23:07:20,701 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:07:20,701 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [663824339] [2023-03-31 23:07:20,701 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:07:20,702 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:07:20,738 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:20,916 INFO L134 CoverageAnalysis]: Checked inductivity of 20 backedges. 0 proven. 16 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:07:20,917 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:07:20,917 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [663824339] [2023-03-31 23:07:20,917 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [663824339] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:07:20,917 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1330217407] [2023-03-31 23:07:20,917 INFO L93 rtionOrderModulation]: Changing assertion order to NOT_INCREMENTALLY [2023-03-31 23:07:20,917 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:20,917 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:07:20,929 INFO L229 MonitoredProcess]: Starting monitored process 19 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:07:20,941 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (19)] Waiting until timeout for monitored process [2023-03-31 23:07:20,987 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:20,988 INFO L262 TraceCheckSpWp]: Trace formula consists of 194 conjuncts, 18 conjunts are in the unsatisfiable core [2023-03-31 23:07:20,989 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:07:21,157 INFO L134 CoverageAnalysis]: Checked inductivity of 20 backedges. 0 proven. 16 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:07:21,157 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-03-31 23:07:21,476 INFO L134 CoverageAnalysis]: Checked inductivity of 20 backedges. 4 proven. 12 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:07:21,476 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1330217407] provided 0 perfect and 2 imperfect interpolant sequences [2023-03-31 23:07:21,476 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [1558301401] [2023-03-31 23:07:21,477 INFO L159 IcfgInterpreter]: Started Sifa with 25 locations of interest [2023-03-31 23:07:21,477 INFO L166 IcfgInterpreter]: Building call graph [2023-03-31 23:07:21,477 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2023-03-31 23:07:21,478 INFO L176 IcfgInterpreter]: Starting interpretation [2023-03-31 23:07:21,478 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2023-03-31 23:07:21,486 INFO L197 IcfgInterpreter]: Interpreting procedure main with input of size 8 for LOIs [2023-03-31 23:07:21,542 INFO L197 IcfgInterpreter]: Interpreting procedure __VERIFIER_assert with input of size 26 for LOIs [2023-03-31 23:07:21,548 INFO L197 IcfgInterpreter]: Interpreting procedure student_version with input of size 19 for LOIs [2023-03-31 23:07:21,579 INFO L197 IcfgInterpreter]: Interpreting procedure correct_version with input of size 19 for LOIs [2023-03-31 23:07:21,625 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.init with input of size 7 for LOIs [2023-03-31 23:07:21,629 INFO L180 IcfgInterpreter]: Interpretation finished [2023-03-31 23:07:22,736 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '9544#(and (= |__VERIFIER_assert_#in~cond| 0) (= __VERIFIER_assert_~cond 0) (= |#NULL.offset| 0) (<= 0 |#StackHeapBarrier|) (= |#NULL.base| 0))' at error location [2023-03-31 23:07:22,736 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2023-03-31 23:07:22,736 INFO L185 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2023-03-31 23:07:22,736 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [13, 13, 13] total 29 [2023-03-31 23:07:22,736 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [813365222] [2023-03-31 23:07:22,736 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2023-03-31 23:07:22,737 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 29 states [2023-03-31 23:07:22,737 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:07:22,737 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 29 interpolants. [2023-03-31 23:07:22,738 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=170, Invalid=2380, Unknown=0, NotChecked=0, Total=2550 [2023-03-31 23:07:22,738 INFO L87 Difference]: Start difference. First operand 94 states and 119 transitions. Second operand has 29 states, 29 states have (on average 1.896551724137931) internal successors, (55), 29 states have internal predecessors, (55), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:07:23,148 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:07:23,148 INFO L93 Difference]: Finished difference Result 106 states and 131 transitions. [2023-03-31 23:07:23,148 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 18 states. [2023-03-31 23:07:23,148 INFO L78 Accepts]: Start accepts. Automaton has has 29 states, 29 states have (on average 1.896551724137931) internal successors, (55), 29 states have internal predecessors, (55), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) Word has length 35 [2023-03-31 23:07:23,148 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:07:23,149 INFO L225 Difference]: With dead ends: 106 [2023-03-31 23:07:23,149 INFO L226 Difference]: Without dead ends: 97 [2023-03-31 23:07:23,150 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 130 GetRequests, 65 SyntacticMatches, 3 SemanticMatches, 62 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 896 ImplicationChecksByTransitivity, 1.7s TimeCoverageRelationStatistics Valid=269, Invalid=3763, Unknown=0, NotChecked=0, Total=4032 [2023-03-31 23:07:23,151 INFO L413 NwaCegarLoop]: 28 mSDtfsCounter, 57 mSDsluCounter, 357 mSDsCounter, 0 mSdLazyCounter, 569 mSolverCounterSat, 9 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.1s Time, 0 mProtectedPredicate, 0 mProtectedAction, 58 SdHoareTripleChecker+Valid, 385 SdHoareTripleChecker+Invalid, 578 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 9 IncrementalHoareTripleChecker+Valid, 569 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.2s IncrementalHoareTripleChecker+Time [2023-03-31 23:07:23,151 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [58 Valid, 385 Invalid, 578 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [9 Valid, 569 Invalid, 0 Unknown, 0 Unchecked, 0.2s Time] [2023-03-31 23:07:23,151 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 97 states. [2023-03-31 23:07:23,169 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 97 to 95. [2023-03-31 23:07:23,169 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 95 states, 71 states have (on average 1.3380281690140845) internal successors, (95), 81 states have internal predecessors, (95), 10 states have call successors, (10), 5 states have call predecessors, (10), 13 states have return successors, (14), 8 states have call predecessors, (14), 8 states have call successors, (14) [2023-03-31 23:07:23,170 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 95 states to 95 states and 119 transitions. [2023-03-31 23:07:23,170 INFO L78 Accepts]: Start accepts. Automaton has 95 states and 119 transitions. Word has length 35 [2023-03-31 23:07:23,170 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:07:23,170 INFO L495 AbstractCegarLoop]: Abstraction has 95 states and 119 transitions. [2023-03-31 23:07:23,171 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 29 states, 29 states have (on average 1.896551724137931) internal successors, (55), 29 states have internal predecessors, (55), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:07:23,171 INFO L276 IsEmpty]: Start isEmpty. Operand 95 states and 119 transitions. [2023-03-31 23:07:23,171 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 36 [2023-03-31 23:07:23,171 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:07:23,171 INFO L195 NwaCegarLoop]: trace histogram [3, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:07:23,187 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (19)] Forceful destruction successful, exit code 0 [2023-03-31 23:07:23,376 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable25,19 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:23,376 INFO L420 AbstractCegarLoop]: === Iteration 27 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:07:23,377 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:07:23,377 INFO L85 PathProgramCache]: Analyzing trace with hash 1420134078, now seen corresponding path program 17 times [2023-03-31 23:07:23,377 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:07:23,377 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1932822245] [2023-03-31 23:07:23,377 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:07:23,377 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:07:23,393 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:23,436 INFO L134 CoverageAnalysis]: Checked inductivity of 17 backedges. 4 proven. 5 refuted. 0 times theorem prover too weak. 8 trivial. 0 not checked. [2023-03-31 23:07:23,437 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:07:23,437 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1932822245] [2023-03-31 23:07:23,437 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1932822245] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:07:23,437 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1412202155] [2023-03-31 23:07:23,437 INFO L93 rtionOrderModulation]: Changing assertion order to OUTSIDE_LOOP_FIRST2 [2023-03-31 23:07:23,437 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:23,437 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:07:23,438 INFO L229 MonitoredProcess]: Starting monitored process 20 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:07:23,449 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (20)] Waiting until timeout for monitored process [2023-03-31 23:07:23,496 INFO L228 tOrderPrioritization]: Assert order OUTSIDE_LOOP_FIRST2 issued 3 check-sat command(s) [2023-03-31 23:07:23,497 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2023-03-31 23:07:23,497 INFO L262 TraceCheckSpWp]: Trace formula consists of 194 conjuncts, 7 conjunts are in the unsatisfiable core [2023-03-31 23:07:23,499 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:07:23,527 INFO L134 CoverageAnalysis]: Checked inductivity of 17 backedges. 6 proven. 3 refuted. 0 times theorem prover too weak. 8 trivial. 0 not checked. [2023-03-31 23:07:23,528 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-03-31 23:07:23,557 INFO L134 CoverageAnalysis]: Checked inductivity of 17 backedges. 6 proven. 3 refuted. 0 times theorem prover too weak. 8 trivial. 0 not checked. [2023-03-31 23:07:23,557 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1412202155] provided 0 perfect and 2 imperfect interpolant sequences [2023-03-31 23:07:23,557 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [1381936071] [2023-03-31 23:07:23,558 INFO L159 IcfgInterpreter]: Started Sifa with 25 locations of interest [2023-03-31 23:07:23,558 INFO L166 IcfgInterpreter]: Building call graph [2023-03-31 23:07:23,558 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2023-03-31 23:07:23,559 INFO L176 IcfgInterpreter]: Starting interpretation [2023-03-31 23:07:23,559 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2023-03-31 23:07:23,567 INFO L197 IcfgInterpreter]: Interpreting procedure main with input of size 8 for LOIs [2023-03-31 23:07:23,628 INFO L197 IcfgInterpreter]: Interpreting procedure __VERIFIER_assert with input of size 26 for LOIs [2023-03-31 23:07:23,634 INFO L197 IcfgInterpreter]: Interpreting procedure student_version with input of size 19 for LOIs [2023-03-31 23:07:23,658 INFO L197 IcfgInterpreter]: Interpreting procedure correct_version with input of size 19 for LOIs [2023-03-31 23:07:23,684 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.init with input of size 7 for LOIs [2023-03-31 23:07:23,686 INFO L180 IcfgInterpreter]: Interpretation finished [2023-03-31 23:07:24,299 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '10160#(and (= |__VERIFIER_assert_#in~cond| 0) (= __VERIFIER_assert_~cond 0) (= |#NULL.offset| 0) (<= 0 |#StackHeapBarrier|) (= |#NULL.base| 0))' at error location [2023-03-31 23:07:24,300 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2023-03-31 23:07:24,300 INFO L185 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2023-03-31 23:07:24,300 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [8, 8, 8] total 13 [2023-03-31 23:07:24,300 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [554406560] [2023-03-31 23:07:24,300 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2023-03-31 23:07:24,300 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 13 states [2023-03-31 23:07:24,300 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:07:24,300 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 13 interpolants. [2023-03-31 23:07:24,301 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=134, Invalid=1056, Unknown=0, NotChecked=0, Total=1190 [2023-03-31 23:07:24,301 INFO L87 Difference]: Start difference. First operand 95 states and 119 transitions. Second operand has 13 states, 13 states have (on average 2.5384615384615383) internal successors, (33), 13 states have internal predecessors, (33), 2 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 2 states have call predecessors, (3), 1 states have call successors, (3) [2023-03-31 23:07:24,357 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:07:24,358 INFO L93 Difference]: Finished difference Result 131 states and 168 transitions. [2023-03-31 23:07:24,358 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 11 states. [2023-03-31 23:07:24,358 INFO L78 Accepts]: Start accepts. Automaton has has 13 states, 13 states have (on average 2.5384615384615383) internal successors, (33), 13 states have internal predecessors, (33), 2 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 2 states have call predecessors, (3), 1 states have call successors, (3) Word has length 35 [2023-03-31 23:07:24,358 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:07:24,359 INFO L225 Difference]: With dead ends: 131 [2023-03-31 23:07:24,359 INFO L226 Difference]: Without dead ends: 117 [2023-03-31 23:07:24,361 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 114 GetRequests, 75 SyntacticMatches, 4 SemanticMatches, 35 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 443 ImplicationChecksByTransitivity, 0.7s TimeCoverageRelationStatistics Valid=151, Invalid=1181, Unknown=0, NotChecked=0, Total=1332 [2023-03-31 23:07:24,364 INFO L413 NwaCegarLoop]: 22 mSDtfsCounter, 12 mSDsluCounter, 106 mSDsCounter, 0 mSdLazyCounter, 75 mSolverCounterSat, 3 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.0s Time, 0 mProtectedPredicate, 0 mProtectedAction, 12 SdHoareTripleChecker+Valid, 128 SdHoareTripleChecker+Invalid, 78 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 3 IncrementalHoareTripleChecker+Valid, 75 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.0s IncrementalHoareTripleChecker+Time [2023-03-31 23:07:24,364 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [12 Valid, 128 Invalid, 78 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [3 Valid, 75 Invalid, 0 Unknown, 0 Unchecked, 0.0s Time] [2023-03-31 23:07:24,364 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 117 states. [2023-03-31 23:07:24,393 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 117 to 113. [2023-03-31 23:07:24,394 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 113 states, 89 states have (on average 1.3258426966292134) internal successors, (118), 99 states have internal predecessors, (118), 10 states have call successors, (10), 5 states have call predecessors, (10), 13 states have return successors, (14), 8 states have call predecessors, (14), 8 states have call successors, (14) [2023-03-31 23:07:24,394 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 113 states to 113 states and 142 transitions. [2023-03-31 23:07:24,394 INFO L78 Accepts]: Start accepts. Automaton has 113 states and 142 transitions. Word has length 35 [2023-03-31 23:07:24,394 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:07:24,394 INFO L495 AbstractCegarLoop]: Abstraction has 113 states and 142 transitions. [2023-03-31 23:07:24,394 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 13 states, 13 states have (on average 2.5384615384615383) internal successors, (33), 13 states have internal predecessors, (33), 2 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 2 states have call predecessors, (3), 1 states have call successors, (3) [2023-03-31 23:07:24,394 INFO L276 IsEmpty]: Start isEmpty. Operand 113 states and 142 transitions. [2023-03-31 23:07:24,395 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 36 [2023-03-31 23:07:24,395 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:07:24,395 INFO L195 NwaCegarLoop]: trace histogram [3, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:07:24,402 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (20)] Forceful destruction successful, exit code 0 [2023-03-31 23:07:24,600 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable26,20 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:24,600 INFO L420 AbstractCegarLoop]: === Iteration 28 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:07:24,601 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:07:24,601 INFO L85 PathProgramCache]: Analyzing trace with hash -1444980633, now seen corresponding path program 18 times [2023-03-31 23:07:24,601 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:07:24,602 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1184422766] [2023-03-31 23:07:24,602 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:07:24,602 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:07:24,610 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:24,658 INFO L134 CoverageAnalysis]: Checked inductivity of 17 backedges. 4 proven. 5 refuted. 0 times theorem prover too weak. 8 trivial. 0 not checked. [2023-03-31 23:07:24,658 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:07:24,658 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1184422766] [2023-03-31 23:07:24,659 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1184422766] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:07:24,659 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1187888542] [2023-03-31 23:07:24,659 INFO L93 rtionOrderModulation]: Changing assertion order to TERMS_WITH_SMALL_CONSTANTS_FIRST [2023-03-31 23:07:24,659 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:24,659 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:07:24,668 INFO L229 MonitoredProcess]: Starting monitored process 21 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:07:24,701 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (21)] Waiting until timeout for monitored process [2023-03-31 23:07:24,733 INFO L228 tOrderPrioritization]: Assert order TERMS_WITH_SMALL_CONSTANTS_FIRST issued 0 check-sat command(s) [2023-03-31 23:07:24,733 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2023-03-31 23:07:24,733 INFO L262 TraceCheckSpWp]: Trace formula consists of 145 conjuncts, 7 conjunts are in the unsatisfiable core [2023-03-31 23:07:24,734 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:07:24,767 INFO L134 CoverageAnalysis]: Checked inductivity of 17 backedges. 6 proven. 3 refuted. 0 times theorem prover too weak. 8 trivial. 0 not checked. [2023-03-31 23:07:24,767 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-03-31 23:07:24,798 INFO L134 CoverageAnalysis]: Checked inductivity of 17 backedges. 6 proven. 3 refuted. 0 times theorem prover too weak. 8 trivial. 0 not checked. [2023-03-31 23:07:24,798 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1187888542] provided 0 perfect and 2 imperfect interpolant sequences [2023-03-31 23:07:24,798 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [2020116667] [2023-03-31 23:07:24,799 INFO L159 IcfgInterpreter]: Started Sifa with 25 locations of interest [2023-03-31 23:07:24,799 INFO L166 IcfgInterpreter]: Building call graph [2023-03-31 23:07:24,799 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2023-03-31 23:07:24,799 INFO L176 IcfgInterpreter]: Starting interpretation [2023-03-31 23:07:24,799 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2023-03-31 23:07:24,807 INFO L197 IcfgInterpreter]: Interpreting procedure main with input of size 8 for LOIs [2023-03-31 23:07:24,860 INFO L197 IcfgInterpreter]: Interpreting procedure __VERIFIER_assert with input of size 26 for LOIs [2023-03-31 23:07:24,866 INFO L197 IcfgInterpreter]: Interpreting procedure student_version with input of size 19 for LOIs [2023-03-31 23:07:24,890 INFO L197 IcfgInterpreter]: Interpreting procedure correct_version with input of size 19 for LOIs [2023-03-31 23:07:24,915 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.init with input of size 7 for LOIs [2023-03-31 23:07:24,917 INFO L180 IcfgInterpreter]: Interpretation finished [2023-03-31 23:07:25,678 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '10834#(and (= |__VERIFIER_assert_#in~cond| 0) (= __VERIFIER_assert_~cond 0) (= |#NULL.offset| 0) (<= 0 |#StackHeapBarrier|) (= |#NULL.base| 0))' at error location [2023-03-31 23:07:25,678 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2023-03-31 23:07:25,678 INFO L185 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2023-03-31 23:07:25,678 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [8, 8, 8] total 13 [2023-03-31 23:07:25,678 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1805274134] [2023-03-31 23:07:25,678 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2023-03-31 23:07:25,678 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 13 states [2023-03-31 23:07:25,678 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:07:25,679 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 13 interpolants. [2023-03-31 23:07:25,679 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=134, Invalid=1056, Unknown=0, NotChecked=0, Total=1190 [2023-03-31 23:07:25,679 INFO L87 Difference]: Start difference. First operand 113 states and 142 transitions. Second operand has 13 states, 13 states have (on average 3.076923076923077) internal successors, (40), 13 states have internal predecessors, (40), 2 states have call successors, (6), 2 states have call predecessors, (6), 2 states have return successors, (4), 2 states have call predecessors, (4), 2 states have call successors, (4) [2023-03-31 23:07:25,763 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:07:25,764 INFO L93 Difference]: Finished difference Result 210 states and 267 transitions. [2023-03-31 23:07:25,764 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 11 states. [2023-03-31 23:07:25,764 INFO L78 Accepts]: Start accepts. Automaton has has 13 states, 13 states have (on average 3.076923076923077) internal successors, (40), 13 states have internal predecessors, (40), 2 states have call successors, (6), 2 states have call predecessors, (6), 2 states have return successors, (4), 2 states have call predecessors, (4), 2 states have call successors, (4) Word has length 35 [2023-03-31 23:07:25,764 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:07:25,765 INFO L225 Difference]: With dead ends: 210 [2023-03-31 23:07:25,765 INFO L226 Difference]: Without dead ends: 135 [2023-03-31 23:07:25,766 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 114 GetRequests, 75 SyntacticMatches, 4 SemanticMatches, 35 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 443 ImplicationChecksByTransitivity, 0.8s TimeCoverageRelationStatistics Valid=151, Invalid=1181, Unknown=0, NotChecked=0, Total=1332 [2023-03-31 23:07:25,766 INFO L413 NwaCegarLoop]: 22 mSDtfsCounter, 10 mSDsluCounter, 149 mSDsCounter, 0 mSdLazyCounter, 102 mSolverCounterSat, 3 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.0s Time, 0 mProtectedPredicate, 0 mProtectedAction, 10 SdHoareTripleChecker+Valid, 171 SdHoareTripleChecker+Invalid, 105 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 3 IncrementalHoareTripleChecker+Valid, 102 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.0s IncrementalHoareTripleChecker+Time [2023-03-31 23:07:25,766 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [10 Valid, 171 Invalid, 105 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [3 Valid, 102 Invalid, 0 Unknown, 0 Unchecked, 0.0s Time] [2023-03-31 23:07:25,767 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 135 states. [2023-03-31 23:07:25,800 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 135 to 131. [2023-03-31 23:07:25,801 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 131 states, 107 states have (on average 1.3177570093457944) internal successors, (141), 117 states have internal predecessors, (141), 10 states have call successors, (10), 5 states have call predecessors, (10), 13 states have return successors, (14), 8 states have call predecessors, (14), 8 states have call successors, (14) [2023-03-31 23:07:25,801 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 131 states to 131 states and 165 transitions. [2023-03-31 23:07:25,801 INFO L78 Accepts]: Start accepts. Automaton has 131 states and 165 transitions. Word has length 35 [2023-03-31 23:07:25,801 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:07:25,801 INFO L495 AbstractCegarLoop]: Abstraction has 131 states and 165 transitions. [2023-03-31 23:07:25,801 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 13 states, 13 states have (on average 3.076923076923077) internal successors, (40), 13 states have internal predecessors, (40), 2 states have call successors, (6), 2 states have call predecessors, (6), 2 states have return successors, (4), 2 states have call predecessors, (4), 2 states have call successors, (4) [2023-03-31 23:07:25,802 INFO L276 IsEmpty]: Start isEmpty. Operand 131 states and 165 transitions. [2023-03-31 23:07:25,802 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 37 [2023-03-31 23:07:25,802 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:07:25,802 INFO L195 NwaCegarLoop]: trace histogram [4, 4, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:07:25,807 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (21)] Forceful destruction successful, exit code 0 [2023-03-31 23:07:26,007 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: 21 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true,SelfDestructingSolverStorable27 [2023-03-31 23:07:26,007 INFO L420 AbstractCegarLoop]: === Iteration 29 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:07:26,007 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:07:26,008 INFO L85 PathProgramCache]: Analyzing trace with hash -6038707, now seen corresponding path program 19 times [2023-03-31 23:07:26,008 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:07:26,008 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [315512498] [2023-03-31 23:07:26,008 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:07:26,008 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:07:26,014 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:26,349 INFO L134 CoverageAnalysis]: Checked inductivity of 24 backedges. 0 proven. 22 refuted. 0 times theorem prover too weak. 2 trivial. 0 not checked. [2023-03-31 23:07:26,349 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:07:26,349 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [315512498] [2023-03-31 23:07:26,349 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [315512498] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:07:26,349 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [528562839] [2023-03-31 23:07:26,349 INFO L93 rtionOrderModulation]: Changing assertion order to NOT_INCREMENTALLY [2023-03-31 23:07:26,350 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:26,350 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:07:26,351 INFO L229 MonitoredProcess]: Starting monitored process 22 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:07:26,352 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (22)] Waiting until timeout for monitored process [2023-03-31 23:07:26,403 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:26,404 INFO L262 TraceCheckSpWp]: Trace formula consists of 199 conjuncts, 46 conjunts are in the unsatisfiable core [2023-03-31 23:07:26,405 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:07:26,546 INFO L134 CoverageAnalysis]: Checked inductivity of 24 backedges. 0 proven. 22 refuted. 0 times theorem prover too weak. 2 trivial. 0 not checked. [2023-03-31 23:07:26,547 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-03-31 23:07:26,722 INFO L134 CoverageAnalysis]: Checked inductivity of 24 backedges. 0 proven. 22 refuted. 0 times theorem prover too weak. 2 trivial. 0 not checked. [2023-03-31 23:07:26,722 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [528562839] provided 0 perfect and 2 imperfect interpolant sequences [2023-03-31 23:07:26,722 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [492206629] [2023-03-31 23:07:26,723 INFO L159 IcfgInterpreter]: Started Sifa with 25 locations of interest [2023-03-31 23:07:26,723 INFO L166 IcfgInterpreter]: Building call graph [2023-03-31 23:07:26,723 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2023-03-31 23:07:26,723 INFO L176 IcfgInterpreter]: Starting interpretation [2023-03-31 23:07:26,723 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2023-03-31 23:07:26,731 INFO L197 IcfgInterpreter]: Interpreting procedure main with input of size 8 for LOIs [2023-03-31 23:07:26,785 INFO L197 IcfgInterpreter]: Interpreting procedure __VERIFIER_assert with input of size 26 for LOIs [2023-03-31 23:07:26,790 INFO L197 IcfgInterpreter]: Interpreting procedure student_version with input of size 19 for LOIs [2023-03-31 23:07:26,815 INFO L197 IcfgInterpreter]: Interpreting procedure correct_version with input of size 19 for LOIs [2023-03-31 23:07:26,839 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.init with input of size 7 for LOIs [2023-03-31 23:07:26,841 INFO L180 IcfgInterpreter]: Interpretation finished [2023-03-31 23:07:27,877 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '11715#(and (= |__VERIFIER_assert_#in~cond| 0) (= __VERIFIER_assert_~cond 0) (= |#NULL.offset| 0) (<= 0 |#StackHeapBarrier|) (= |#NULL.base| 0))' at error location [2023-03-31 23:07:27,877 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2023-03-31 23:07:27,877 INFO L185 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2023-03-31 23:07:27,877 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [24, 24, 24] total 30 [2023-03-31 23:07:27,877 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [675548076] [2023-03-31 23:07:27,877 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2023-03-31 23:07:27,878 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 30 states [2023-03-31 23:07:27,878 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:07:27,879 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 30 interpolants. [2023-03-31 23:07:27,879 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=155, Invalid=2497, Unknown=0, NotChecked=0, Total=2652 [2023-03-31 23:07:27,879 INFO L87 Difference]: Start difference. First operand 131 states and 165 transitions. Second operand has 30 states, 25 states have (on average 1.4) internal successors, (35), 25 states have internal predecessors, (35), 4 states have call successors, (6), 3 states have call predecessors, (6), 3 states have return successors, (4), 4 states have call predecessors, (4), 2 states have call successors, (4) [2023-03-31 23:07:28,345 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:07:28,345 INFO L93 Difference]: Finished difference Result 167 states and 210 transitions. [2023-03-31 23:07:28,346 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 25 states. [2023-03-31 23:07:28,346 INFO L78 Accepts]: Start accepts. Automaton has has 30 states, 25 states have (on average 1.4) internal successors, (35), 25 states have internal predecessors, (35), 4 states have call successors, (6), 3 states have call predecessors, (6), 3 states have return successors, (4), 4 states have call predecessors, (4), 2 states have call successors, (4) Word has length 36 [2023-03-31 23:07:28,346 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:07:28,347 INFO L225 Difference]: With dead ends: 167 [2023-03-31 23:07:28,347 INFO L226 Difference]: Without dead ends: 161 [2023-03-31 23:07:28,348 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 137 GetRequests, 74 SyntacticMatches, 7 SemanticMatches, 56 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 514 ImplicationChecksByTransitivity, 1.5s TimeCoverageRelationStatistics Valid=185, Invalid=3121, Unknown=0, NotChecked=0, Total=3306 [2023-03-31 23:07:28,348 INFO L413 NwaCegarLoop]: 24 mSDtfsCounter, 34 mSDsluCounter, 506 mSDsCounter, 0 mSdLazyCounter, 1072 mSolverCounterSat, 1 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.3s Time, 0 mProtectedPredicate, 0 mProtectedAction, 39 SdHoareTripleChecker+Valid, 530 SdHoareTripleChecker+Invalid, 1073 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 1 IncrementalHoareTripleChecker+Valid, 1072 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.3s IncrementalHoareTripleChecker+Time [2023-03-31 23:07:28,348 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [39 Valid, 530 Invalid, 1073 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [1 Valid, 1072 Invalid, 0 Unknown, 0 Unchecked, 0.3s Time] [2023-03-31 23:07:28,348 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 161 states. [2023-03-31 23:07:28,376 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 161 to 141. [2023-03-31 23:07:28,376 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 141 states, 114 states have (on average 1.3157894736842106) internal successors, (150), 126 states have internal predecessors, (150), 11 states have call successors, (11), 5 states have call predecessors, (11), 15 states have return successors, (17), 9 states have call predecessors, (17), 9 states have call successors, (17) [2023-03-31 23:07:28,377 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 141 states to 141 states and 178 transitions. [2023-03-31 23:07:28,377 INFO L78 Accepts]: Start accepts. Automaton has 141 states and 178 transitions. Word has length 36 [2023-03-31 23:07:28,377 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:07:28,377 INFO L495 AbstractCegarLoop]: Abstraction has 141 states and 178 transitions. [2023-03-31 23:07:28,377 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 30 states, 25 states have (on average 1.4) internal successors, (35), 25 states have internal predecessors, (35), 4 states have call successors, (6), 3 states have call predecessors, (6), 3 states have return successors, (4), 4 states have call predecessors, (4), 2 states have call successors, (4) [2023-03-31 23:07:28,378 INFO L276 IsEmpty]: Start isEmpty. Operand 141 states and 178 transitions. [2023-03-31 23:07:28,378 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 37 [2023-03-31 23:07:28,378 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:07:28,378 INFO L195 NwaCegarLoop]: trace histogram [3, 3, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:07:28,383 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (22)] Forceful destruction successful, exit code 0 [2023-03-31 23:07:28,583 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: 22 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true,SelfDestructingSolverStorable28 [2023-03-31 23:07:28,583 INFO L420 AbstractCegarLoop]: === Iteration 30 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:07:28,583 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:07:28,583 INFO L85 PathProgramCache]: Analyzing trace with hash -518418070, now seen corresponding path program 20 times [2023-03-31 23:07:28,583 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:07:28,583 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1906612190] [2023-03-31 23:07:28,583 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:07:28,584 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:07:28,589 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:28,680 INFO L134 CoverageAnalysis]: Checked inductivity of 20 backedges. 0 proven. 9 refuted. 0 times theorem prover too weak. 11 trivial. 0 not checked. [2023-03-31 23:07:28,680 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:07:28,680 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1906612190] [2023-03-31 23:07:28,680 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1906612190] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:07:28,680 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [585559512] [2023-03-31 23:07:28,680 INFO L93 rtionOrderModulation]: Changing assertion order to OUTSIDE_LOOP_FIRST2 [2023-03-31 23:07:28,680 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:28,681 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:07:28,682 INFO L229 MonitoredProcess]: Starting monitored process 23 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:07:28,684 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (23)] Waiting until timeout for monitored process [2023-03-31 23:07:28,732 INFO L228 tOrderPrioritization]: Assert order OUTSIDE_LOOP_FIRST2 issued 3 check-sat command(s) [2023-03-31 23:07:28,733 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2023-03-31 23:07:28,733 INFO L262 TraceCheckSpWp]: Trace formula consists of 199 conjuncts, 16 conjunts are in the unsatisfiable core [2023-03-31 23:07:28,734 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:07:28,844 INFO L134 CoverageAnalysis]: Checked inductivity of 20 backedges. 0 proven. 9 refuted. 0 times theorem prover too weak. 11 trivial. 0 not checked. [2023-03-31 23:07:28,844 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-03-31 23:07:29,011 INFO L134 CoverageAnalysis]: Checked inductivity of 20 backedges. 3 proven. 6 refuted. 0 times theorem prover too weak. 11 trivial. 0 not checked. [2023-03-31 23:07:29,012 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [585559512] provided 0 perfect and 2 imperfect interpolant sequences [2023-03-31 23:07:29,012 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [720658024] [2023-03-31 23:07:29,021 INFO L159 IcfgInterpreter]: Started Sifa with 25 locations of interest [2023-03-31 23:07:29,021 INFO L166 IcfgInterpreter]: Building call graph [2023-03-31 23:07:29,022 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2023-03-31 23:07:29,022 INFO L176 IcfgInterpreter]: Starting interpretation [2023-03-31 23:07:29,022 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2023-03-31 23:07:29,053 INFO L197 IcfgInterpreter]: Interpreting procedure main with input of size 8 for LOIs [2023-03-31 23:07:29,149 INFO L197 IcfgInterpreter]: Interpreting procedure __VERIFIER_assert with input of size 26 for LOIs [2023-03-31 23:07:29,155 INFO L197 IcfgInterpreter]: Interpreting procedure student_version with input of size 19 for LOIs [2023-03-31 23:07:29,189 INFO L197 IcfgInterpreter]: Interpreting procedure correct_version with input of size 19 for LOIs [2023-03-31 23:07:29,214 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.init with input of size 7 for LOIs [2023-03-31 23:07:29,216 INFO L180 IcfgInterpreter]: Interpretation finished [2023-03-31 23:07:29,961 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '12540#(and (= |__VERIFIER_assert_#in~cond| 0) (= __VERIFIER_assert_~cond 0) (= |#NULL.offset| 0) (<= 0 |#StackHeapBarrier|) (= |#NULL.base| 0))' at error location [2023-03-31 23:07:29,961 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2023-03-31 23:07:29,961 INFO L185 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2023-03-31 23:07:29,961 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [11, 11, 11] total 23 [2023-03-31 23:07:29,962 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [502384270] [2023-03-31 23:07:29,962 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2023-03-31 23:07:29,963 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 23 states [2023-03-31 23:07:29,963 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:07:29,963 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 23 interpolants. [2023-03-31 23:07:29,963 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=149, Invalid=1831, Unknown=0, NotChecked=0, Total=1980 [2023-03-31 23:07:29,964 INFO L87 Difference]: Start difference. First operand 141 states and 178 transitions. Second operand has 23 states, 23 states have (on average 1.7826086956521738) internal successors, (41), 23 states have internal predecessors, (41), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:07:30,240 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:07:30,240 INFO L93 Difference]: Finished difference Result 165 states and 208 transitions. [2023-03-31 23:07:30,240 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 14 states. [2023-03-31 23:07:30,240 INFO L78 Accepts]: Start accepts. Automaton has has 23 states, 23 states have (on average 1.7826086956521738) internal successors, (41), 23 states have internal predecessors, (41), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) Word has length 36 [2023-03-31 23:07:30,241 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:07:30,241 INFO L225 Difference]: With dead ends: 165 [2023-03-31 23:07:30,241 INFO L226 Difference]: Without dead ends: 153 [2023-03-31 23:07:30,242 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 127 GetRequests, 72 SyntacticMatches, 3 SemanticMatches, 52 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 602 ImplicationChecksByTransitivity, 1.0s TimeCoverageRelationStatistics Valid=210, Invalid=2652, Unknown=0, NotChecked=0, Total=2862 [2023-03-31 23:07:30,243 INFO L413 NwaCegarLoop]: 23 mSDtfsCounter, 54 mSDsluCounter, 226 mSDsCounter, 0 mSdLazyCounter, 414 mSolverCounterSat, 5 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.1s Time, 0 mProtectedPredicate, 0 mProtectedAction, 56 SdHoareTripleChecker+Valid, 249 SdHoareTripleChecker+Invalid, 419 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 5 IncrementalHoareTripleChecker+Valid, 414 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.1s IncrementalHoareTripleChecker+Time [2023-03-31 23:07:30,243 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [56 Valid, 249 Invalid, 419 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [5 Valid, 414 Invalid, 0 Unknown, 0 Unchecked, 0.1s Time] [2023-03-31 23:07:30,243 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 153 states. [2023-03-31 23:07:30,298 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 153 to 150. [2023-03-31 23:07:30,298 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 150 states, 114 states have (on average 1.3070175438596492) internal successors, (149), 132 states have internal predecessors, (149), 14 states have call successors, (14), 5 states have call predecessors, (14), 21 states have return successors, (26), 12 states have call predecessors, (26), 12 states have call successors, (26) [2023-03-31 23:07:30,298 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 150 states to 150 states and 189 transitions. [2023-03-31 23:07:30,299 INFO L78 Accepts]: Start accepts. Automaton has 150 states and 189 transitions. Word has length 36 [2023-03-31 23:07:30,299 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:07:30,299 INFO L495 AbstractCegarLoop]: Abstraction has 150 states and 189 transitions. [2023-03-31 23:07:30,299 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 23 states, 23 states have (on average 1.7826086956521738) internal successors, (41), 23 states have internal predecessors, (41), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:07:30,299 INFO L276 IsEmpty]: Start isEmpty. Operand 150 states and 189 transitions. [2023-03-31 23:07:30,314 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 37 [2023-03-31 23:07:30,314 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:07:30,314 INFO L195 NwaCegarLoop]: trace histogram [2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:07:30,335 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (23)] Forceful destruction successful, exit code 0 [2023-03-31 23:07:30,514 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable29,23 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:30,515 INFO L420 AbstractCegarLoop]: === Iteration 31 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:07:30,515 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:07:30,515 INFO L85 PathProgramCache]: Analyzing trace with hash -1438870489, now seen corresponding path program 21 times [2023-03-31 23:07:30,515 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:07:30,515 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1366917838] [2023-03-31 23:07:30,515 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:07:30,515 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:07:30,521 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:30,794 INFO L134 CoverageAnalysis]: Checked inductivity of 18 backedges. 0 proven. 12 refuted. 0 times theorem prover too weak. 6 trivial. 0 not checked. [2023-03-31 23:07:30,794 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:07:30,794 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1366917838] [2023-03-31 23:07:30,794 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1366917838] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:07:30,795 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [505510965] [2023-03-31 23:07:30,796 INFO L93 rtionOrderModulation]: Changing assertion order to TERMS_WITH_SMALL_CONSTANTS_FIRST [2023-03-31 23:07:30,797 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:30,797 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:07:30,798 INFO L229 MonitoredProcess]: Starting monitored process 24 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:07:30,799 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (24)] Waiting until timeout for monitored process [2023-03-31 23:07:30,851 INFO L228 tOrderPrioritization]: Assert order TERMS_WITH_SMALL_CONSTANTS_FIRST issued 0 check-sat command(s) [2023-03-31 23:07:30,851 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2023-03-31 23:07:30,852 INFO L262 TraceCheckSpWp]: Trace formula consists of 199 conjuncts, 42 conjunts are in the unsatisfiable core [2023-03-31 23:07:30,853 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:07:31,030 INFO L134 CoverageAnalysis]: Checked inductivity of 18 backedges. 0 proven. 12 refuted. 0 times theorem prover too weak. 6 trivial. 0 not checked. [2023-03-31 23:07:31,031 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-03-31 23:07:31,197 INFO L134 CoverageAnalysis]: Checked inductivity of 18 backedges. 0 proven. 12 refuted. 0 times theorem prover too weak. 6 trivial. 0 not checked. [2023-03-31 23:07:31,197 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [505510965] provided 0 perfect and 2 imperfect interpolant sequences [2023-03-31 23:07:31,197 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [479196948] [2023-03-31 23:07:31,198 INFO L159 IcfgInterpreter]: Started Sifa with 25 locations of interest [2023-03-31 23:07:31,198 INFO L166 IcfgInterpreter]: Building call graph [2023-03-31 23:07:31,198 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2023-03-31 23:07:31,198 INFO L176 IcfgInterpreter]: Starting interpretation [2023-03-31 23:07:31,198 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2023-03-31 23:07:31,206 INFO L197 IcfgInterpreter]: Interpreting procedure main with input of size 8 for LOIs [2023-03-31 23:07:31,273 INFO L197 IcfgInterpreter]: Interpreting procedure __VERIFIER_assert with input of size 26 for LOIs [2023-03-31 23:07:31,279 INFO L197 IcfgInterpreter]: Interpreting procedure student_version with input of size 19 for LOIs [2023-03-31 23:07:31,304 INFO L197 IcfgInterpreter]: Interpreting procedure correct_version with input of size 19 for LOIs [2023-03-31 23:07:31,329 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.init with input of size 7 for LOIs [2023-03-31 23:07:31,331 INFO L180 IcfgInterpreter]: Interpretation finished [2023-03-31 23:07:32,422 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '13373#(and (= |__VERIFIER_assert_#in~cond| 0) (= __VERIFIER_assert_~cond 0) (= |#NULL.offset| 0) (<= 0 |#StackHeapBarrier|) (= |#NULL.base| 0))' at error location [2023-03-31 23:07:32,422 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2023-03-31 23:07:32,422 INFO L185 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2023-03-31 23:07:32,423 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [22, 22, 22] total 30 [2023-03-31 23:07:32,423 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1821955466] [2023-03-31 23:07:32,423 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2023-03-31 23:07:32,423 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 30 states [2023-03-31 23:07:32,423 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:07:32,423 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 30 interpolants. [2023-03-31 23:07:32,424 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=159, Invalid=2493, Unknown=0, NotChecked=0, Total=2652 [2023-03-31 23:07:32,424 INFO L87 Difference]: Start difference. First operand 150 states and 189 transitions. Second operand has 30 states, 25 states have (on average 1.48) internal successors, (37), 25 states have internal predecessors, (37), 4 states have call successors, (6), 3 states have call predecessors, (6), 3 states have return successors, (4), 4 states have call predecessors, (4), 2 states have call successors, (4) [2023-03-31 23:07:32,708 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:07:32,709 INFO L93 Difference]: Finished difference Result 164 states and 207 transitions. [2023-03-31 23:07:32,709 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 23 states. [2023-03-31 23:07:32,709 INFO L78 Accepts]: Start accepts. Automaton has has 30 states, 25 states have (on average 1.48) internal successors, (37), 25 states have internal predecessors, (37), 4 states have call successors, (6), 3 states have call predecessors, (6), 3 states have return successors, (4), 4 states have call predecessors, (4), 2 states have call successors, (4) Word has length 36 [2023-03-31 23:07:32,709 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:07:32,710 INFO L225 Difference]: With dead ends: 164 [2023-03-31 23:07:32,710 INFO L226 Difference]: Without dead ends: 152 [2023-03-31 23:07:32,711 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 135 GetRequests, 70 SyntacticMatches, 9 SemanticMatches, 56 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 600 ImplicationChecksByTransitivity, 1.4s TimeCoverageRelationStatistics Valid=189, Invalid=3117, Unknown=0, NotChecked=0, Total=3306 [2023-03-31 23:07:32,711 INFO L413 NwaCegarLoop]: 21 mSDtfsCounter, 21 mSDsluCounter, 406 mSDsCounter, 0 mSdLazyCounter, 694 mSolverCounterSat, 1 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.1s Time, 0 mProtectedPredicate, 0 mProtectedAction, 23 SdHoareTripleChecker+Valid, 427 SdHoareTripleChecker+Invalid, 695 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 1 IncrementalHoareTripleChecker+Valid, 694 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.1s IncrementalHoareTripleChecker+Time [2023-03-31 23:07:32,711 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [23 Valid, 427 Invalid, 695 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [1 Valid, 694 Invalid, 0 Unknown, 0 Unchecked, 0.1s Time] [2023-03-31 23:07:32,711 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 152 states. [2023-03-31 23:07:32,746 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 152 to 149. [2023-03-31 23:07:32,747 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 149 states, 113 states have (on average 1.3185840707964602) internal successors, (149), 131 states have internal predecessors, (149), 14 states have call successors, (14), 5 states have call predecessors, (14), 21 states have return successors, (26), 12 states have call predecessors, (26), 12 states have call successors, (26) [2023-03-31 23:07:32,747 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 149 states to 149 states and 189 transitions. [2023-03-31 23:07:32,747 INFO L78 Accepts]: Start accepts. Automaton has 149 states and 189 transitions. Word has length 36 [2023-03-31 23:07:32,748 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:07:32,748 INFO L495 AbstractCegarLoop]: Abstraction has 149 states and 189 transitions. [2023-03-31 23:07:32,748 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 30 states, 25 states have (on average 1.48) internal successors, (37), 25 states have internal predecessors, (37), 4 states have call successors, (6), 3 states have call predecessors, (6), 3 states have return successors, (4), 4 states have call predecessors, (4), 2 states have call successors, (4) [2023-03-31 23:07:32,748 INFO L276 IsEmpty]: Start isEmpty. Operand 149 states and 189 transitions. [2023-03-31 23:07:32,749 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 37 [2023-03-31 23:07:32,749 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:07:32,749 INFO L195 NwaCegarLoop]: trace histogram [3, 3, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:07:32,753 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (24)] Forceful destruction successful, exit code 0 [2023-03-31 23:07:32,953 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable30,24 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:32,954 INFO L420 AbstractCegarLoop]: === Iteration 32 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:07:32,954 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:07:32,954 INFO L85 PathProgramCache]: Analyzing trace with hash 1398021564, now seen corresponding path program 22 times [2023-03-31 23:07:32,954 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:07:32,954 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [462784868] [2023-03-31 23:07:32,954 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:07:32,954 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:07:32,960 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:33,108 INFO L134 CoverageAnalysis]: Checked inductivity of 20 backedges. 0 proven. 11 refuted. 0 times theorem prover too weak. 9 trivial. 0 not checked. [2023-03-31 23:07:33,110 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:07:33,110 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [462784868] [2023-03-31 23:07:33,110 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [462784868] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:07:33,110 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [281115464] [2023-03-31 23:07:33,110 INFO L93 rtionOrderModulation]: Changing assertion order to NOT_INCREMENTALLY [2023-03-31 23:07:33,110 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:33,110 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:07:33,124 INFO L229 MonitoredProcess]: Starting monitored process 25 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:07:33,124 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (25)] Waiting until timeout for monitored process [2023-03-31 23:07:33,174 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:33,175 INFO L262 TraceCheckSpWp]: Trace formula consists of 199 conjuncts, 16 conjunts are in the unsatisfiable core [2023-03-31 23:07:33,176 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:07:33,256 INFO L134 CoverageAnalysis]: Checked inductivity of 20 backedges. 0 proven. 9 refuted. 0 times theorem prover too weak. 11 trivial. 0 not checked. [2023-03-31 23:07:33,257 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-03-31 23:07:33,407 INFO L134 CoverageAnalysis]: Checked inductivity of 20 backedges. 3 proven. 6 refuted. 0 times theorem prover too weak. 11 trivial. 0 not checked. [2023-03-31 23:07:33,407 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [281115464] provided 0 perfect and 2 imperfect interpolant sequences [2023-03-31 23:07:33,407 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [1093554533] [2023-03-31 23:07:33,421 INFO L159 IcfgInterpreter]: Started Sifa with 25 locations of interest [2023-03-31 23:07:33,421 INFO L166 IcfgInterpreter]: Building call graph [2023-03-31 23:07:33,421 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2023-03-31 23:07:33,421 INFO L176 IcfgInterpreter]: Starting interpretation [2023-03-31 23:07:33,421 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2023-03-31 23:07:33,437 INFO L197 IcfgInterpreter]: Interpreting procedure main with input of size 8 for LOIs [2023-03-31 23:07:33,493 INFO L197 IcfgInterpreter]: Interpreting procedure __VERIFIER_assert with input of size 26 for LOIs [2023-03-31 23:07:33,501 INFO L197 IcfgInterpreter]: Interpreting procedure student_version with input of size 19 for LOIs [2023-03-31 23:07:33,527 INFO L197 IcfgInterpreter]: Interpreting procedure correct_version with input of size 19 for LOIs [2023-03-31 23:07:33,550 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.init with input of size 7 for LOIs [2023-03-31 23:07:33,552 INFO L180 IcfgInterpreter]: Interpretation finished [2023-03-31 23:07:34,622 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '14191#(and (= |__VERIFIER_assert_#in~cond| 0) (= __VERIFIER_assert_~cond 0) (= |#NULL.offset| 0) (<= 0 |#StackHeapBarrier|) (= |#NULL.base| 0))' at error location [2023-03-31 23:07:34,623 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2023-03-31 23:07:34,623 INFO L185 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2023-03-31 23:07:34,623 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [13, 11, 11] total 25 [2023-03-31 23:07:34,623 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1712884636] [2023-03-31 23:07:34,623 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2023-03-31 23:07:34,623 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 25 states [2023-03-31 23:07:34,623 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:07:34,624 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 25 interpolants. [2023-03-31 23:07:34,624 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=159, Invalid=2003, Unknown=0, NotChecked=0, Total=2162 [2023-03-31 23:07:34,624 INFO L87 Difference]: Start difference. First operand 149 states and 189 transitions. Second operand has 25 states, 25 states have (on average 1.76) internal successors, (44), 25 states have internal predecessors, (44), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:07:34,966 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:07:34,966 INFO L93 Difference]: Finished difference Result 159 states and 198 transitions. [2023-03-31 23:07:34,967 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 14 states. [2023-03-31 23:07:34,967 INFO L78 Accepts]: Start accepts. Automaton has has 25 states, 25 states have (on average 1.76) internal successors, (44), 25 states have internal predecessors, (44), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) Word has length 36 [2023-03-31 23:07:34,967 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:07:34,968 INFO L225 Difference]: With dead ends: 159 [2023-03-31 23:07:34,968 INFO L226 Difference]: Without dead ends: 145 [2023-03-31 23:07:34,970 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 128 GetRequests, 72 SyntacticMatches, 3 SemanticMatches, 53 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 549 ImplicationChecksByTransitivity, 1.4s TimeCoverageRelationStatistics Valid=219, Invalid=2751, Unknown=0, NotChecked=0, Total=2970 [2023-03-31 23:07:34,970 INFO L413 NwaCegarLoop]: 23 mSDtfsCounter, 77 mSDsluCounter, 304 mSDsCounter, 0 mSdLazyCounter, 535 mSolverCounterSat, 6 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.1s Time, 0 mProtectedPredicate, 0 mProtectedAction, 78 SdHoareTripleChecker+Valid, 327 SdHoareTripleChecker+Invalid, 541 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 6 IncrementalHoareTripleChecker+Valid, 535 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.2s IncrementalHoareTripleChecker+Time [2023-03-31 23:07:34,971 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [78 Valid, 327 Invalid, 541 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [6 Valid, 535 Invalid, 0 Unknown, 0 Unchecked, 0.2s Time] [2023-03-31 23:07:34,971 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 145 states. [2023-03-31 23:07:35,003 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 145 to 143. [2023-03-31 23:07:35,004 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 143 states, 107 states have (on average 1.3177570093457944) internal successors, (141), 125 states have internal predecessors, (141), 14 states have call successors, (14), 5 states have call predecessors, (14), 21 states have return successors, (24), 12 states have call predecessors, (24), 12 states have call successors, (24) [2023-03-31 23:07:35,004 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 143 states to 143 states and 179 transitions. [2023-03-31 23:07:35,005 INFO L78 Accepts]: Start accepts. Automaton has 143 states and 179 transitions. Word has length 36 [2023-03-31 23:07:35,005 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:07:35,005 INFO L495 AbstractCegarLoop]: Abstraction has 143 states and 179 transitions. [2023-03-31 23:07:35,005 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 25 states, 25 states have (on average 1.76) internal successors, (44), 25 states have internal predecessors, (44), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:07:35,005 INFO L276 IsEmpty]: Start isEmpty. Operand 143 states and 179 transitions. [2023-03-31 23:07:35,007 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 38 [2023-03-31 23:07:35,007 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:07:35,007 INFO L195 NwaCegarLoop]: trace histogram [5, 4, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:07:35,014 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (25)] Forceful destruction successful, exit code 0 [2023-03-31 23:07:35,212 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable31,25 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:35,212 INFO L420 AbstractCegarLoop]: === Iteration 33 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:07:35,212 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:07:35,212 INFO L85 PathProgramCache]: Analyzing trace with hash -70615260, now seen corresponding path program 23 times [2023-03-31 23:07:35,212 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:07:35,212 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1227478944] [2023-03-31 23:07:35,212 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:07:35,213 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:07:35,219 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:35,364 INFO L134 CoverageAnalysis]: Checked inductivity of 29 backedges. 0 proven. 25 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:07:35,364 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:07:35,364 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1227478944] [2023-03-31 23:07:35,364 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1227478944] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:07:35,364 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [255100937] [2023-03-31 23:07:35,364 INFO L93 rtionOrderModulation]: Changing assertion order to OUTSIDE_LOOP_FIRST2 [2023-03-31 23:07:35,364 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:35,364 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:07:35,378 INFO L229 MonitoredProcess]: Starting monitored process 26 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:07:35,381 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (26)] Waiting until timeout for monitored process [2023-03-31 23:07:35,438 INFO L228 tOrderPrioritization]: Assert order OUTSIDE_LOOP_FIRST2 issued 4 check-sat command(s) [2023-03-31 23:07:35,439 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2023-03-31 23:07:35,439 INFO L262 TraceCheckSpWp]: Trace formula consists of 204 conjuncts, 20 conjunts are in the unsatisfiable core [2023-03-31 23:07:35,441 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:07:35,651 INFO L134 CoverageAnalysis]: Checked inductivity of 29 backedges. 0 proven. 25 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:07:35,651 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-03-31 23:07:36,034 INFO L134 CoverageAnalysis]: Checked inductivity of 29 backedges. 5 proven. 20 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:07:36,034 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [255100937] provided 0 perfect and 2 imperfect interpolant sequences [2023-03-31 23:07:36,034 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [58768591] [2023-03-31 23:07:36,035 INFO L159 IcfgInterpreter]: Started Sifa with 25 locations of interest [2023-03-31 23:07:36,035 INFO L166 IcfgInterpreter]: Building call graph [2023-03-31 23:07:36,035 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2023-03-31 23:07:36,035 INFO L176 IcfgInterpreter]: Starting interpretation [2023-03-31 23:07:36,035 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2023-03-31 23:07:36,060 INFO L197 IcfgInterpreter]: Interpreting procedure main with input of size 8 for LOIs [2023-03-31 23:07:36,111 INFO L197 IcfgInterpreter]: Interpreting procedure __VERIFIER_assert with input of size 26 for LOIs [2023-03-31 23:07:36,118 INFO L197 IcfgInterpreter]: Interpreting procedure student_version with input of size 19 for LOIs [2023-03-31 23:07:36,143 INFO L197 IcfgInterpreter]: Interpreting procedure correct_version with input of size 19 for LOIs [2023-03-31 23:07:36,167 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.init with input of size 7 for LOIs [2023-03-31 23:07:36,169 INFO L180 IcfgInterpreter]: Interpretation finished [2023-03-31 23:07:37,111 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '15008#(and (= |__VERIFIER_assert_#in~cond| 0) (= __VERIFIER_assert_~cond 0) (= |#NULL.offset| 0) (<= 0 |#StackHeapBarrier|) (= |#NULL.base| 0))' at error location [2023-03-31 23:07:37,111 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2023-03-31 23:07:37,111 INFO L185 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2023-03-31 23:07:37,111 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [15, 15, 15] total 35 [2023-03-31 23:07:37,111 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1304074878] [2023-03-31 23:07:37,111 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2023-03-31 23:07:37,112 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 35 states [2023-03-31 23:07:37,112 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:07:37,112 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 35 interpolants. [2023-03-31 23:07:37,112 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=190, Invalid=3002, Unknown=0, NotChecked=0, Total=3192 [2023-03-31 23:07:37,113 INFO L87 Difference]: Start difference. First operand 143 states and 179 transitions. Second operand has 35 states, 35 states have (on average 1.7428571428571429) internal successors, (61), 35 states have internal predecessors, (61), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:07:37,741 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:07:37,742 INFO L93 Difference]: Finished difference Result 175 states and 220 transitions. [2023-03-31 23:07:37,742 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 22 states. [2023-03-31 23:07:37,742 INFO L78 Accepts]: Start accepts. Automaton has has 35 states, 35 states have (on average 1.7428571428571429) internal successors, (61), 35 states have internal predecessors, (61), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) Word has length 37 [2023-03-31 23:07:37,742 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:07:37,743 INFO L225 Difference]: With dead ends: 175 [2023-03-31 23:07:37,743 INFO L226 Difference]: Without dead ends: 164 [2023-03-31 23:07:37,744 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 142 GetRequests, 67 SyntacticMatches, 3 SemanticMatches, 72 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 1235 ImplicationChecksByTransitivity, 1.6s TimeCoverageRelationStatistics Valid=333, Invalid=5069, Unknown=0, NotChecked=0, Total=5402 [2023-03-31 23:07:37,745 INFO L413 NwaCegarLoop]: 25 mSDtfsCounter, 78 mSDsluCounter, 523 mSDsCounter, 0 mSdLazyCounter, 1097 mSolverCounterSat, 14 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.2s Time, 0 mProtectedPredicate, 0 mProtectedAction, 82 SdHoareTripleChecker+Valid, 548 SdHoareTripleChecker+Invalid, 1111 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 14 IncrementalHoareTripleChecker+Valid, 1097 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.3s IncrementalHoareTripleChecker+Time [2023-03-31 23:07:37,745 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [82 Valid, 548 Invalid, 1111 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [14 Valid, 1097 Invalid, 0 Unknown, 0 Unchecked, 0.3s Time] [2023-03-31 23:07:37,746 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 164 states. [2023-03-31 23:07:37,782 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 164 to 158. [2023-03-31 23:07:37,782 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 158 states, 119 states have (on average 1.319327731092437) internal successors, (157), 139 states have internal predecessors, (157), 15 states have call successors, (15), 5 states have call predecessors, (15), 23 states have return successors, (27), 13 states have call predecessors, (27), 13 states have call successors, (27) [2023-03-31 23:07:37,783 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 158 states to 158 states and 199 transitions. [2023-03-31 23:07:37,784 INFO L78 Accepts]: Start accepts. Automaton has 158 states and 199 transitions. Word has length 37 [2023-03-31 23:07:37,784 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:07:37,784 INFO L495 AbstractCegarLoop]: Abstraction has 158 states and 199 transitions. [2023-03-31 23:07:37,784 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 35 states, 35 states have (on average 1.7428571428571429) internal successors, (61), 35 states have internal predecessors, (61), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:07:37,784 INFO L276 IsEmpty]: Start isEmpty. Operand 158 states and 199 transitions. [2023-03-31 23:07:37,785 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 38 [2023-03-31 23:07:37,785 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:07:37,785 INFO L195 NwaCegarLoop]: trace histogram [5, 4, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:07:37,797 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (26)] Forceful destruction successful, exit code 0 [2023-03-31 23:07:37,990 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: 26 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true,SelfDestructingSolverStorable32 [2023-03-31 23:07:37,990 INFO L420 AbstractCegarLoop]: === Iteration 34 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:07:37,990 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:07:37,990 INFO L85 PathProgramCache]: Analyzing trace with hash 1203706965, now seen corresponding path program 24 times [2023-03-31 23:07:37,990 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:07:37,991 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1515676221] [2023-03-31 23:07:37,991 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:07:37,991 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:07:38,007 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:38,156 INFO L134 CoverageAnalysis]: Checked inductivity of 29 backedges. 0 proven. 25 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:07:38,157 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:07:38,157 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1515676221] [2023-03-31 23:07:38,157 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1515676221] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:07:38,157 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1975122378] [2023-03-31 23:07:38,157 INFO L93 rtionOrderModulation]: Changing assertion order to TERMS_WITH_SMALL_CONSTANTS_FIRST [2023-03-31 23:07:38,157 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:38,157 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:07:38,158 INFO L229 MonitoredProcess]: Starting monitored process 27 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:07:38,160 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (27)] Waiting until timeout for monitored process [2023-03-31 23:07:38,208 INFO L228 tOrderPrioritization]: Assert order TERMS_WITH_SMALL_CONSTANTS_FIRST issued 0 check-sat command(s) [2023-03-31 23:07:38,208 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2023-03-31 23:07:38,209 INFO L262 TraceCheckSpWp]: Trace formula consists of 155 conjuncts, 20 conjunts are in the unsatisfiable core [2023-03-31 23:07:38,210 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:07:38,433 INFO L134 CoverageAnalysis]: Checked inductivity of 29 backedges. 0 proven. 25 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:07:38,434 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-03-31 23:07:38,794 INFO L134 CoverageAnalysis]: Checked inductivity of 29 backedges. 5 proven. 20 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:07:38,795 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1975122378] provided 0 perfect and 2 imperfect interpolant sequences [2023-03-31 23:07:38,795 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [1032182210] [2023-03-31 23:07:38,795 INFO L159 IcfgInterpreter]: Started Sifa with 25 locations of interest [2023-03-31 23:07:38,795 INFO L166 IcfgInterpreter]: Building call graph [2023-03-31 23:07:38,796 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2023-03-31 23:07:38,796 INFO L176 IcfgInterpreter]: Starting interpretation [2023-03-31 23:07:38,796 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2023-03-31 23:07:38,805 INFO L197 IcfgInterpreter]: Interpreting procedure main with input of size 8 for LOIs [2023-03-31 23:07:38,864 INFO L197 IcfgInterpreter]: Interpreting procedure __VERIFIER_assert with input of size 26 for LOIs [2023-03-31 23:07:38,870 INFO L197 IcfgInterpreter]: Interpreting procedure student_version with input of size 19 for LOIs [2023-03-31 23:07:38,895 INFO L197 IcfgInterpreter]: Interpreting procedure correct_version with input of size 19 for LOIs [2023-03-31 23:07:38,919 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.init with input of size 7 for LOIs [2023-03-31 23:07:38,921 INFO L180 IcfgInterpreter]: Interpretation finished [2023-03-31 23:07:39,785 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '15898#(and (= |__VERIFIER_assert_#in~cond| 0) (= __VERIFIER_assert_~cond 0) (= |#NULL.offset| 0) (<= 0 |#StackHeapBarrier|) (= |#NULL.base| 0))' at error location [2023-03-31 23:07:39,785 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2023-03-31 23:07:39,785 INFO L185 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2023-03-31 23:07:39,785 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [15, 15, 15] total 35 [2023-03-31 23:07:39,785 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1849493916] [2023-03-31 23:07:39,785 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2023-03-31 23:07:39,785 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 35 states [2023-03-31 23:07:39,785 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:07:39,786 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 35 interpolants. [2023-03-31 23:07:39,786 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=190, Invalid=3002, Unknown=0, NotChecked=0, Total=3192 [2023-03-31 23:07:39,786 INFO L87 Difference]: Start difference. First operand 158 states and 199 transitions. Second operand has 35 states, 35 states have (on average 1.7428571428571429) internal successors, (61), 35 states have internal predecessors, (61), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:07:40,419 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:07:40,419 INFO L93 Difference]: Finished difference Result 170 states and 211 transitions. [2023-03-31 23:07:40,419 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 22 states. [2023-03-31 23:07:40,420 INFO L78 Accepts]: Start accepts. Automaton has has 35 states, 35 states have (on average 1.7428571428571429) internal successors, (61), 35 states have internal predecessors, (61), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) Word has length 37 [2023-03-31 23:07:40,420 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:07:40,420 INFO L225 Difference]: With dead ends: 170 [2023-03-31 23:07:40,420 INFO L226 Difference]: Without dead ends: 161 [2023-03-31 23:07:40,421 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 142 GetRequests, 67 SyntacticMatches, 3 SemanticMatches, 72 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 1235 ImplicationChecksByTransitivity, 1.6s TimeCoverageRelationStatistics Valid=333, Invalid=5069, Unknown=0, NotChecked=0, Total=5402 [2023-03-31 23:07:40,422 INFO L413 NwaCegarLoop]: 30 mSDtfsCounter, 81 mSDsluCounter, 601 mSDsCounter, 0 mSdLazyCounter, 1022 mSolverCounterSat, 14 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.3s Time, 0 mProtectedPredicate, 0 mProtectedAction, 82 SdHoareTripleChecker+Valid, 631 SdHoareTripleChecker+Invalid, 1036 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 14 IncrementalHoareTripleChecker+Valid, 1022 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.3s IncrementalHoareTripleChecker+Time [2023-03-31 23:07:40,422 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [82 Valid, 631 Invalid, 1036 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [14 Valid, 1022 Invalid, 0 Unknown, 0 Unchecked, 0.3s Time] [2023-03-31 23:07:40,422 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 161 states. [2023-03-31 23:07:40,461 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 161 to 159. [2023-03-31 23:07:40,461 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 159 states, 120 states have (on average 1.3166666666666667) internal successors, (158), 140 states have internal predecessors, (158), 15 states have call successors, (15), 5 states have call predecessors, (15), 23 states have return successors, (25), 13 states have call predecessors, (25), 13 states have call successors, (25) [2023-03-31 23:07:40,462 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 159 states to 159 states and 198 transitions. [2023-03-31 23:07:40,462 INFO L78 Accepts]: Start accepts. Automaton has 159 states and 198 transitions. Word has length 37 [2023-03-31 23:07:40,462 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:07:40,462 INFO L495 AbstractCegarLoop]: Abstraction has 159 states and 198 transitions. [2023-03-31 23:07:40,462 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 35 states, 35 states have (on average 1.7428571428571429) internal successors, (61), 35 states have internal predecessors, (61), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:07:40,462 INFO L276 IsEmpty]: Start isEmpty. Operand 159 states and 198 transitions. [2023-03-31 23:07:40,466 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 38 [2023-03-31 23:07:40,466 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:07:40,466 INFO L195 NwaCegarLoop]: trace histogram [3, 3, 3, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:07:40,483 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (27)] Forceful destruction successful, exit code 0 [2023-03-31 23:07:40,671 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: 27 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true,SelfDestructingSolverStorable33 [2023-03-31 23:07:40,671 INFO L420 AbstractCegarLoop]: === Iteration 35 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:07:40,671 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:07:40,671 INFO L85 PathProgramCache]: Analyzing trace with hash 1715304117, now seen corresponding path program 25 times [2023-03-31 23:07:40,671 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:07:40,672 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1720810092] [2023-03-31 23:07:40,672 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:07:40,672 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:07:40,677 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:40,719 INFO L134 CoverageAnalysis]: Checked inductivity of 23 backedges. 3 proven. 6 refuted. 0 times theorem prover too weak. 14 trivial. 0 not checked. [2023-03-31 23:07:40,719 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:07:40,719 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1720810092] [2023-03-31 23:07:40,719 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1720810092] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:07:40,719 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1127233682] [2023-03-31 23:07:40,719 INFO L93 rtionOrderModulation]: Changing assertion order to NOT_INCREMENTALLY [2023-03-31 23:07:40,720 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:40,720 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:07:40,721 INFO L229 MonitoredProcess]: Starting monitored process 28 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:07:40,745 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (28)] Waiting until timeout for monitored process [2023-03-31 23:07:40,780 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:40,780 INFO L262 TraceCheckSpWp]: Trace formula consists of 204 conjuncts, 8 conjunts are in the unsatisfiable core [2023-03-31 23:07:40,781 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:07:40,804 INFO L134 CoverageAnalysis]: Checked inductivity of 23 backedges. 6 proven. 3 refuted. 0 times theorem prover too weak. 14 trivial. 0 not checked. [2023-03-31 23:07:40,805 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-03-31 23:07:40,830 INFO L134 CoverageAnalysis]: Checked inductivity of 23 backedges. 6 proven. 3 refuted. 0 times theorem prover too weak. 14 trivial. 0 not checked. [2023-03-31 23:07:40,830 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1127233682] provided 0 perfect and 2 imperfect interpolant sequences [2023-03-31 23:07:40,830 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [828078220] [2023-03-31 23:07:40,831 INFO L159 IcfgInterpreter]: Started Sifa with 25 locations of interest [2023-03-31 23:07:40,831 INFO L166 IcfgInterpreter]: Building call graph [2023-03-31 23:07:40,832 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2023-03-31 23:07:40,832 INFO L176 IcfgInterpreter]: Starting interpretation [2023-03-31 23:07:40,832 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2023-03-31 23:07:40,842 INFO L197 IcfgInterpreter]: Interpreting procedure main with input of size 8 for LOIs [2023-03-31 23:07:40,916 INFO L197 IcfgInterpreter]: Interpreting procedure __VERIFIER_assert with input of size 26 for LOIs [2023-03-31 23:07:40,921 INFO L197 IcfgInterpreter]: Interpreting procedure student_version with input of size 19 for LOIs [2023-03-31 23:07:40,945 INFO L197 IcfgInterpreter]: Interpreting procedure correct_version with input of size 19 for LOIs [2023-03-31 23:07:40,969 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.init with input of size 7 for LOIs [2023-03-31 23:07:40,971 INFO L180 IcfgInterpreter]: Interpretation finished [2023-03-31 23:07:41,499 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '16761#(and (= |__VERIFIER_assert_#in~cond| 0) (= __VERIFIER_assert_~cond 0) (= |#NULL.offset| 0) (<= 0 |#StackHeapBarrier|) (= |#NULL.base| 0))' at error location [2023-03-31 23:07:41,499 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2023-03-31 23:07:41,499 INFO L185 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2023-03-31 23:07:41,500 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [9, 9, 9] total 14 [2023-03-31 23:07:41,500 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [493611336] [2023-03-31 23:07:41,500 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2023-03-31 23:07:41,500 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 14 states [2023-03-31 23:07:41,501 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:07:41,501 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 14 interpolants. [2023-03-31 23:07:41,502 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=154, Invalid=1106, Unknown=0, NotChecked=0, Total=1260 [2023-03-31 23:07:41,502 INFO L87 Difference]: Start difference. First operand 159 states and 198 transitions. Second operand has 14 states, 14 states have (on average 2.857142857142857) internal successors, (40), 14 states have internal predecessors, (40), 2 states have call successors, (6), 2 states have call predecessors, (6), 2 states have return successors, (4), 2 states have call predecessors, (4), 2 states have call successors, (4) [2023-03-31 23:07:41,591 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:07:41,591 INFO L93 Difference]: Finished difference Result 239 states and 291 transitions. [2023-03-31 23:07:41,591 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 12 states. [2023-03-31 23:07:41,591 INFO L78 Accepts]: Start accepts. Automaton has has 14 states, 14 states have (on average 2.857142857142857) internal successors, (40), 14 states have internal predecessors, (40), 2 states have call successors, (6), 2 states have call predecessors, (6), 2 states have return successors, (4), 2 states have call predecessors, (4), 2 states have call successors, (4) Word has length 37 [2023-03-31 23:07:41,591 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:07:41,592 INFO L225 Difference]: With dead ends: 239 [2023-03-31 23:07:41,592 INFO L226 Difference]: Without dead ends: 156 [2023-03-31 23:07:41,593 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 122 GetRequests, 79 SyntacticMatches, 6 SemanticMatches, 37 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 568 ImplicationChecksByTransitivity, 0.6s TimeCoverageRelationStatistics Valid=186, Invalid=1296, Unknown=0, NotChecked=0, Total=1482 [2023-03-31 23:07:41,602 INFO L413 NwaCegarLoop]: 25 mSDtfsCounter, 26 mSDsluCounter, 74 mSDsCounter, 0 mSdLazyCounter, 84 mSolverCounterSat, 2 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.0s Time, 0 mProtectedPredicate, 0 mProtectedAction, 26 SdHoareTripleChecker+Valid, 99 SdHoareTripleChecker+Invalid, 86 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 2 IncrementalHoareTripleChecker+Valid, 84 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.0s IncrementalHoareTripleChecker+Time [2023-03-31 23:07:41,604 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [26 Valid, 99 Invalid, 86 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [2 Valid, 84 Invalid, 0 Unknown, 0 Unchecked, 0.0s Time] [2023-03-31 23:07:41,604 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 156 states. [2023-03-31 23:07:41,670 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 156 to 152. [2023-03-31 23:07:41,671 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 152 states, 119 states have (on average 1.2857142857142858) internal successors, (153), 135 states have internal predecessors, (153), 13 states have call successors, (13), 5 states have call predecessors, (13), 19 states have return successors, (19), 11 states have call predecessors, (19), 11 states have call successors, (19) [2023-03-31 23:07:41,671 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 152 states to 152 states and 185 transitions. [2023-03-31 23:07:41,671 INFO L78 Accepts]: Start accepts. Automaton has 152 states and 185 transitions. Word has length 37 [2023-03-31 23:07:41,672 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:07:41,672 INFO L495 AbstractCegarLoop]: Abstraction has 152 states and 185 transitions. [2023-03-31 23:07:41,672 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 14 states, 14 states have (on average 2.857142857142857) internal successors, (40), 14 states have internal predecessors, (40), 2 states have call successors, (6), 2 states have call predecessors, (6), 2 states have return successors, (4), 2 states have call predecessors, (4), 2 states have call successors, (4) [2023-03-31 23:07:41,672 INFO L276 IsEmpty]: Start isEmpty. Operand 152 states and 185 transitions. [2023-03-31 23:07:41,687 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 38 [2023-03-31 23:07:41,687 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:07:41,688 INFO L195 NwaCegarLoop]: trace histogram [3, 3, 3, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:07:41,693 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (28)] Forceful destruction successful, exit code 0 [2023-03-31 23:07:41,898 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: 28 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true,SelfDestructingSolverStorable34 [2023-03-31 23:07:41,898 INFO L420 AbstractCegarLoop]: === Iteration 36 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:07:41,898 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:07:41,899 INFO L85 PathProgramCache]: Analyzing trace with hash 1802831596, now seen corresponding path program 26 times [2023-03-31 23:07:41,899 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:07:41,899 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1905997881] [2023-03-31 23:07:41,899 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:07:41,899 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:07:41,907 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:41,952 INFO L134 CoverageAnalysis]: Checked inductivity of 23 backedges. 3 proven. 6 refuted. 0 times theorem prover too weak. 14 trivial. 0 not checked. [2023-03-31 23:07:41,952 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:07:41,952 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1905997881] [2023-03-31 23:07:41,952 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1905997881] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:07:41,952 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [863518342] [2023-03-31 23:07:41,952 INFO L93 rtionOrderModulation]: Changing assertion order to OUTSIDE_LOOP_FIRST2 [2023-03-31 23:07:41,952 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:41,953 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:07:41,953 INFO L229 MonitoredProcess]: Starting monitored process 29 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:07:41,969 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (29)] Waiting until timeout for monitored process [2023-03-31 23:07:42,033 INFO L228 tOrderPrioritization]: Assert order OUTSIDE_LOOP_FIRST2 issued 3 check-sat command(s) [2023-03-31 23:07:42,033 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2023-03-31 23:07:42,034 INFO L262 TraceCheckSpWp]: Trace formula consists of 204 conjuncts, 8 conjunts are in the unsatisfiable core [2023-03-31 23:07:42,035 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:07:42,071 INFO L134 CoverageAnalysis]: Checked inductivity of 23 backedges. 6 proven. 3 refuted. 0 times theorem prover too weak. 14 trivial. 0 not checked. [2023-03-31 23:07:42,072 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-03-31 23:07:42,114 INFO L134 CoverageAnalysis]: Checked inductivity of 23 backedges. 6 proven. 3 refuted. 0 times theorem prover too weak. 14 trivial. 0 not checked. [2023-03-31 23:07:42,114 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [863518342] provided 0 perfect and 2 imperfect interpolant sequences [2023-03-31 23:07:42,114 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [1774496401] [2023-03-31 23:07:42,114 INFO L159 IcfgInterpreter]: Started Sifa with 25 locations of interest [2023-03-31 23:07:42,115 INFO L166 IcfgInterpreter]: Building call graph [2023-03-31 23:07:42,115 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2023-03-31 23:07:42,115 INFO L176 IcfgInterpreter]: Starting interpretation [2023-03-31 23:07:42,115 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2023-03-31 23:07:42,122 INFO L197 IcfgInterpreter]: Interpreting procedure main with input of size 8 for LOIs [2023-03-31 23:07:42,177 INFO L197 IcfgInterpreter]: Interpreting procedure __VERIFIER_assert with input of size 26 for LOIs [2023-03-31 23:07:42,183 INFO L197 IcfgInterpreter]: Interpreting procedure student_version with input of size 19 for LOIs [2023-03-31 23:07:42,207 INFO L197 IcfgInterpreter]: Interpreting procedure correct_version with input of size 19 for LOIs [2023-03-31 23:07:42,231 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.init with input of size 7 for LOIs [2023-03-31 23:07:42,233 INFO L180 IcfgInterpreter]: Interpretation finished [2023-03-31 23:07:42,865 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '17711#(and (= |__VERIFIER_assert_#in~cond| 0) (= __VERIFIER_assert_~cond 0) (= |#NULL.offset| 0) (<= 0 |#StackHeapBarrier|) (= |#NULL.base| 0))' at error location [2023-03-31 23:07:42,866 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2023-03-31 23:07:42,866 INFO L185 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2023-03-31 23:07:42,872 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [9, 9, 9] total 14 [2023-03-31 23:07:42,873 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [2128651154] [2023-03-31 23:07:42,873 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2023-03-31 23:07:42,873 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 14 states [2023-03-31 23:07:42,873 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:07:42,877 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 14 interpolants. [2023-03-31 23:07:42,877 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=154, Invalid=1106, Unknown=0, NotChecked=0, Total=1260 [2023-03-31 23:07:42,877 INFO L87 Difference]: Start difference. First operand 152 states and 185 transitions. Second operand has 14 states, 14 states have (on average 2.357142857142857) internal successors, (33), 14 states have internal predecessors, (33), 2 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 2 states have call predecessors, (3), 1 states have call successors, (3) [2023-03-31 23:07:42,955 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:07:42,955 INFO L93 Difference]: Finished difference Result 168 states and 205 transitions. [2023-03-31 23:07:42,956 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 12 states. [2023-03-31 23:07:42,956 INFO L78 Accepts]: Start accepts. Automaton has has 14 states, 14 states have (on average 2.357142857142857) internal successors, (33), 14 states have internal predecessors, (33), 2 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 2 states have call predecessors, (3), 1 states have call successors, (3) Word has length 37 [2023-03-31 23:07:42,956 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:07:42,957 INFO L225 Difference]: With dead ends: 168 [2023-03-31 23:07:42,957 INFO L226 Difference]: Without dead ends: 157 [2023-03-31 23:07:42,973 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 122 GetRequests, 79 SyntacticMatches, 6 SemanticMatches, 37 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 569 ImplicationChecksByTransitivity, 0.7s TimeCoverageRelationStatistics Valid=186, Invalid=1296, Unknown=0, NotChecked=0, Total=1482 [2023-03-31 23:07:42,977 INFO L413 NwaCegarLoop]: 23 mSDtfsCounter, 21 mSDsluCounter, 107 mSDsCounter, 0 mSdLazyCounter, 84 mSolverCounterSat, 3 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.0s Time, 0 mProtectedPredicate, 0 mProtectedAction, 21 SdHoareTripleChecker+Valid, 130 SdHoareTripleChecker+Invalid, 87 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 3 IncrementalHoareTripleChecker+Valid, 84 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.0s IncrementalHoareTripleChecker+Time [2023-03-31 23:07:42,977 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [21 Valid, 130 Invalid, 87 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [3 Valid, 84 Invalid, 0 Unknown, 0 Unchecked, 0.0s Time] [2023-03-31 23:07:42,978 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 157 states. [2023-03-31 23:07:43,023 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 157 to 157. [2023-03-31 23:07:43,023 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 157 states, 124 states have (on average 1.2741935483870968) internal successors, (158), 140 states have internal predecessors, (158), 13 states have call successors, (13), 5 states have call predecessors, (13), 19 states have return successors, (19), 11 states have call predecessors, (19), 11 states have call successors, (19) [2023-03-31 23:07:43,023 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 157 states to 157 states and 190 transitions. [2023-03-31 23:07:43,024 INFO L78 Accepts]: Start accepts. Automaton has 157 states and 190 transitions. Word has length 37 [2023-03-31 23:07:43,024 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:07:43,024 INFO L495 AbstractCegarLoop]: Abstraction has 157 states and 190 transitions. [2023-03-31 23:07:43,024 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 14 states, 14 states have (on average 2.357142857142857) internal successors, (33), 14 states have internal predecessors, (33), 2 states have call successors, (5), 2 states have call predecessors, (5), 2 states have return successors, (3), 2 states have call predecessors, (3), 1 states have call successors, (3) [2023-03-31 23:07:43,024 INFO L276 IsEmpty]: Start isEmpty. Operand 157 states and 190 transitions. [2023-03-31 23:07:43,025 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 39 [2023-03-31 23:07:43,025 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:07:43,025 INFO L195 NwaCegarLoop]: trace histogram [5, 5, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:07:43,029 INFO L552 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (29)] Ended with exit code 0 [2023-03-31 23:07:43,229 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable35,29 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:43,230 INFO L420 AbstractCegarLoop]: === Iteration 37 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:07:43,230 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:07:43,230 INFO L85 PathProgramCache]: Analyzing trace with hash -1223205092, now seen corresponding path program 27 times [2023-03-31 23:07:43,230 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:07:43,230 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [2073933652] [2023-03-31 23:07:43,230 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:07:43,231 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:07:43,238 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:43,565 INFO L134 CoverageAnalysis]: Checked inductivity of 34 backedges. 0 proven. 32 refuted. 0 times theorem prover too weak. 2 trivial. 0 not checked. [2023-03-31 23:07:43,565 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:07:43,565 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [2073933652] [2023-03-31 23:07:43,565 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [2073933652] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:07:43,565 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1037003064] [2023-03-31 23:07:43,565 INFO L93 rtionOrderModulation]: Changing assertion order to TERMS_WITH_SMALL_CONSTANTS_FIRST [2023-03-31 23:07:43,566 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:43,566 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:07:43,567 INFO L229 MonitoredProcess]: Starting monitored process 30 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:07:43,568 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (30)] Waiting until timeout for monitored process [2023-03-31 23:07:43,628 INFO L228 tOrderPrioritization]: Assert order TERMS_WITH_SMALL_CONSTANTS_FIRST issued 0 check-sat command(s) [2023-03-31 23:07:43,629 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2023-03-31 23:07:43,630 INFO L262 TraceCheckSpWp]: Trace formula consists of 209 conjuncts, 50 conjunts are in the unsatisfiable core [2023-03-31 23:07:43,630 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:07:43,725 INFO L134 CoverageAnalysis]: Checked inductivity of 34 backedges. 0 proven. 32 refuted. 0 times theorem prover too weak. 2 trivial. 0 not checked. [2023-03-31 23:07:43,726 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-03-31 23:07:43,850 INFO L134 CoverageAnalysis]: Checked inductivity of 34 backedges. 0 proven. 32 refuted. 0 times theorem prover too weak. 2 trivial. 0 not checked. [2023-03-31 23:07:43,850 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1037003064] provided 0 perfect and 2 imperfect interpolant sequences [2023-03-31 23:07:43,851 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [130754078] [2023-03-31 23:07:43,851 INFO L159 IcfgInterpreter]: Started Sifa with 25 locations of interest [2023-03-31 23:07:43,851 INFO L166 IcfgInterpreter]: Building call graph [2023-03-31 23:07:43,851 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2023-03-31 23:07:43,852 INFO L176 IcfgInterpreter]: Starting interpretation [2023-03-31 23:07:43,852 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2023-03-31 23:07:43,863 INFO L197 IcfgInterpreter]: Interpreting procedure main with input of size 8 for LOIs [2023-03-31 23:07:43,951 INFO L197 IcfgInterpreter]: Interpreting procedure __VERIFIER_assert with input of size 26 for LOIs [2023-03-31 23:07:43,957 INFO L197 IcfgInterpreter]: Interpreting procedure student_version with input of size 19 for LOIs [2023-03-31 23:07:43,981 INFO L197 IcfgInterpreter]: Interpreting procedure correct_version with input of size 19 for LOIs [2023-03-31 23:07:44,008 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.init with input of size 7 for LOIs [2023-03-31 23:07:44,010 INFO L180 IcfgInterpreter]: Interpretation finished [2023-03-31 23:07:44,858 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '18571#(and (= |__VERIFIER_assert_#in~cond| 0) (= __VERIFIER_assert_~cond 0) (= |#NULL.offset| 0) (<= 0 |#StackHeapBarrier|) (= |#NULL.base| 0))' at error location [2023-03-31 23:07:44,858 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2023-03-31 23:07:44,858 INFO L185 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2023-03-31 23:07:44,858 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [26, 26, 26] total 32 [2023-03-31 23:07:44,858 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [485435991] [2023-03-31 23:07:44,858 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2023-03-31 23:07:44,858 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 32 states [2023-03-31 23:07:44,858 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:07:44,859 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 32 interpolants. [2023-03-31 23:07:44,859 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=159, Invalid=2703, Unknown=0, NotChecked=0, Total=2862 [2023-03-31 23:07:44,859 INFO L87 Difference]: Start difference. First operand 157 states and 190 transitions. Second operand has 32 states, 27 states have (on average 1.3703703703703705) internal successors, (37), 27 states have internal predecessors, (37), 4 states have call successors, (6), 3 states have call predecessors, (6), 3 states have return successors, (4), 4 states have call predecessors, (4), 2 states have call successors, (4) [2023-03-31 23:07:45,288 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:07:45,289 INFO L93 Difference]: Finished difference Result 197 states and 239 transitions. [2023-03-31 23:07:45,289 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 27 states. [2023-03-31 23:07:45,289 INFO L78 Accepts]: Start accepts. Automaton has has 32 states, 27 states have (on average 1.3703703703703705) internal successors, (37), 27 states have internal predecessors, (37), 4 states have call successors, (6), 3 states have call predecessors, (6), 3 states have return successors, (4), 4 states have call predecessors, (4), 2 states have call successors, (4) Word has length 38 [2023-03-31 23:07:45,289 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:07:45,290 INFO L225 Difference]: With dead ends: 197 [2023-03-31 23:07:45,290 INFO L226 Difference]: Without dead ends: 191 [2023-03-31 23:07:45,291 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 145 GetRequests, 80 SyntacticMatches, 7 SemanticMatches, 58 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 515 ImplicationChecksByTransitivity, 1.2s TimeCoverageRelationStatistics Valid=189, Invalid=3351, Unknown=0, NotChecked=0, Total=3540 [2023-03-31 23:07:45,291 INFO L413 NwaCegarLoop]: 27 mSDtfsCounter, 39 mSDsluCounter, 624 mSDsCounter, 0 mSdLazyCounter, 1365 mSolverCounterSat, 1 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.2s Time, 0 mProtectedPredicate, 0 mProtectedAction, 44 SdHoareTripleChecker+Valid, 651 SdHoareTripleChecker+Invalid, 1366 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 1 IncrementalHoareTripleChecker+Valid, 1365 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.3s IncrementalHoareTripleChecker+Time [2023-03-31 23:07:45,291 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [44 Valid, 651 Invalid, 1366 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [1 Valid, 1365 Invalid, 0 Unknown, 0 Unchecked, 0.3s Time] [2023-03-31 23:07:45,292 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 191 states. [2023-03-31 23:07:45,339 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 191 to 167. [2023-03-31 23:07:45,339 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 167 states, 131 states have (on average 1.2748091603053435) internal successors, (167), 149 states have internal predecessors, (167), 14 states have call successors, (14), 5 states have call predecessors, (14), 21 states have return successors, (22), 12 states have call predecessors, (22), 12 states have call successors, (22) [2023-03-31 23:07:45,340 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 167 states to 167 states and 203 transitions. [2023-03-31 23:07:45,340 INFO L78 Accepts]: Start accepts. Automaton has 167 states and 203 transitions. Word has length 38 [2023-03-31 23:07:45,340 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:07:45,340 INFO L495 AbstractCegarLoop]: Abstraction has 167 states and 203 transitions. [2023-03-31 23:07:45,340 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 32 states, 27 states have (on average 1.3703703703703705) internal successors, (37), 27 states have internal predecessors, (37), 4 states have call successors, (6), 3 states have call predecessors, (6), 3 states have return successors, (4), 4 states have call predecessors, (4), 2 states have call successors, (4) [2023-03-31 23:07:45,340 INFO L276 IsEmpty]: Start isEmpty. Operand 167 states and 203 transitions. [2023-03-31 23:07:45,343 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 39 [2023-03-31 23:07:45,343 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:07:45,343 INFO L195 NwaCegarLoop]: trace histogram [3, 3, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:07:45,359 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (30)] Forceful destruction successful, exit code 0 [2023-03-31 23:07:45,547 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: 30 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true,SelfDestructingSolverStorable36 [2023-03-31 23:07:45,548 INFO L420 AbstractCegarLoop]: === Iteration 38 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:07:45,548 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:07:45,548 INFO L85 PathProgramCache]: Analyzing trace with hash -1011400086, now seen corresponding path program 28 times [2023-03-31 23:07:45,548 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:07:45,548 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [487703680] [2023-03-31 23:07:45,548 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:07:45,548 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:07:45,558 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:45,847 INFO L134 CoverageAnalysis]: Checked inductivity of 24 backedges. 0 proven. 18 refuted. 0 times theorem prover too weak. 6 trivial. 0 not checked. [2023-03-31 23:07:45,848 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:07:45,848 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [487703680] [2023-03-31 23:07:45,848 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [487703680] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:07:45,848 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1338932718] [2023-03-31 23:07:45,848 INFO L93 rtionOrderModulation]: Changing assertion order to NOT_INCREMENTALLY [2023-03-31 23:07:45,848 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:45,848 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:07:45,849 INFO L229 MonitoredProcess]: Starting monitored process 31 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:07:45,851 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (31)] Waiting until timeout for monitored process [2023-03-31 23:07:45,906 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:45,907 INFO L262 TraceCheckSpWp]: Trace formula consists of 209 conjuncts, 46 conjunts are in the unsatisfiable core [2023-03-31 23:07:45,907 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:07:46,110 INFO L134 CoverageAnalysis]: Checked inductivity of 24 backedges. 0 proven. 18 refuted. 0 times theorem prover too weak. 6 trivial. 0 not checked. [2023-03-31 23:07:46,110 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-03-31 23:07:46,244 INFO L134 CoverageAnalysis]: Checked inductivity of 24 backedges. 0 proven. 18 refuted. 0 times theorem prover too weak. 6 trivial. 0 not checked. [2023-03-31 23:07:46,244 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1338932718] provided 0 perfect and 2 imperfect interpolant sequences [2023-03-31 23:07:46,244 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [2084891757] [2023-03-31 23:07:46,246 INFO L159 IcfgInterpreter]: Started Sifa with 25 locations of interest [2023-03-31 23:07:46,246 INFO L166 IcfgInterpreter]: Building call graph [2023-03-31 23:07:46,246 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2023-03-31 23:07:46,247 INFO L176 IcfgInterpreter]: Starting interpretation [2023-03-31 23:07:46,247 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2023-03-31 23:07:46,258 INFO L197 IcfgInterpreter]: Interpreting procedure main with input of size 8 for LOIs [2023-03-31 23:07:46,311 INFO L197 IcfgInterpreter]: Interpreting procedure __VERIFIER_assert with input of size 26 for LOIs [2023-03-31 23:07:46,316 INFO L197 IcfgInterpreter]: Interpreting procedure student_version with input of size 19 for LOIs [2023-03-31 23:07:46,340 INFO L197 IcfgInterpreter]: Interpreting procedure correct_version with input of size 19 for LOIs [2023-03-31 23:07:46,364 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.init with input of size 7 for LOIs [2023-03-31 23:07:46,366 INFO L180 IcfgInterpreter]: Interpretation finished [2023-03-31 23:07:47,208 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '19509#(and (= |__VERIFIER_assert_#in~cond| 0) (= __VERIFIER_assert_~cond 0) (= |#NULL.offset| 0) (<= 0 |#StackHeapBarrier|) (= |#NULL.base| 0))' at error location [2023-03-31 23:07:47,209 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2023-03-31 23:07:47,209 INFO L185 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2023-03-31 23:07:47,209 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [24, 24, 24] total 32 [2023-03-31 23:07:47,209 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1256857406] [2023-03-31 23:07:47,209 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2023-03-31 23:07:47,210 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 32 states [2023-03-31 23:07:47,210 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:07:47,210 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 32 interpolants. [2023-03-31 23:07:47,211 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=163, Invalid=2699, Unknown=0, NotChecked=0, Total=2862 [2023-03-31 23:07:47,211 INFO L87 Difference]: Start difference. First operand 167 states and 203 transitions. Second operand has 32 states, 27 states have (on average 1.4444444444444444) internal successors, (39), 27 states have internal predecessors, (39), 4 states have call successors, (6), 3 states have call predecessors, (6), 3 states have return successors, (4), 4 states have call predecessors, (4), 2 states have call successors, (4) [2023-03-31 23:07:47,518 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:07:47,519 INFO L93 Difference]: Finished difference Result 173 states and 208 transitions. [2023-03-31 23:07:47,519 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 25 states. [2023-03-31 23:07:47,519 INFO L78 Accepts]: Start accepts. Automaton has has 32 states, 27 states have (on average 1.4444444444444444) internal successors, (39), 27 states have internal predecessors, (39), 4 states have call successors, (6), 3 states have call predecessors, (6), 3 states have return successors, (4), 4 states have call predecessors, (4), 2 states have call successors, (4) Word has length 38 [2023-03-31 23:07:47,519 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:07:47,521 INFO L225 Difference]: With dead ends: 173 [2023-03-31 23:07:47,521 INFO L226 Difference]: Without dead ends: 157 [2023-03-31 23:07:47,538 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 143 GetRequests, 76 SyntacticMatches, 9 SemanticMatches, 58 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 601 ImplicationChecksByTransitivity, 1.3s TimeCoverageRelationStatistics Valid=193, Invalid=3347, Unknown=0, NotChecked=0, Total=3540 [2023-03-31 23:07:47,538 INFO L413 NwaCegarLoop]: 26 mSDtfsCounter, 26 mSDsluCounter, 598 mSDsCounter, 0 mSdLazyCounter, 1020 mSolverCounterSat, 1 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.2s Time, 0 mProtectedPredicate, 0 mProtectedAction, 27 SdHoareTripleChecker+Valid, 624 SdHoareTripleChecker+Invalid, 1021 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 1 IncrementalHoareTripleChecker+Valid, 1020 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.2s IncrementalHoareTripleChecker+Time [2023-03-31 23:07:47,538 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [27 Valid, 624 Invalid, 1021 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [1 Valid, 1020 Invalid, 0 Unknown, 0 Unchecked, 0.2s Time] [2023-03-31 23:07:47,538 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 157 states. [2023-03-31 23:07:47,583 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 157 to 157. [2023-03-31 23:07:47,583 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 157 states, 124 states have (on average 1.2741935483870968) internal successors, (158), 140 states have internal predecessors, (158), 13 states have call successors, (13), 5 states have call predecessors, (13), 19 states have return successors, (20), 11 states have call predecessors, (20), 11 states have call successors, (20) [2023-03-31 23:07:47,584 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 157 states to 157 states and 191 transitions. [2023-03-31 23:07:47,584 INFO L78 Accepts]: Start accepts. Automaton has 157 states and 191 transitions. Word has length 38 [2023-03-31 23:07:47,584 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:07:47,584 INFO L495 AbstractCegarLoop]: Abstraction has 157 states and 191 transitions. [2023-03-31 23:07:47,584 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 32 states, 27 states have (on average 1.4444444444444444) internal successors, (39), 27 states have internal predecessors, (39), 4 states have call successors, (6), 3 states have call predecessors, (6), 3 states have return successors, (4), 4 states have call predecessors, (4), 2 states have call successors, (4) [2023-03-31 23:07:47,584 INFO L276 IsEmpty]: Start isEmpty. Operand 157 states and 191 transitions. [2023-03-31 23:07:47,585 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 39 [2023-03-31 23:07:47,585 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:07:47,585 INFO L195 NwaCegarLoop]: trace histogram [3, 3, 3, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:07:47,590 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (31)] Forceful destruction successful, exit code 0 [2023-03-31 23:07:47,790 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: 31 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true,SelfDestructingSolverStorable37 [2023-03-31 23:07:47,790 INFO L420 AbstractCegarLoop]: === Iteration 39 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:07:47,790 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:07:47,790 INFO L85 PathProgramCache]: Analyzing trace with hash -1296046244, now seen corresponding path program 29 times [2023-03-31 23:07:47,790 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:07:47,791 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [413578343] [2023-03-31 23:07:47,791 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:07:47,791 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:07:47,797 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:48,070 INFO L134 CoverageAnalysis]: Checked inductivity of 26 backedges. 0 proven. 14 refuted. 0 times theorem prover too weak. 12 trivial. 0 not checked. [2023-03-31 23:07:48,071 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:07:48,071 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [413578343] [2023-03-31 23:07:48,071 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [413578343] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:07:48,071 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1742875694] [2023-03-31 23:07:48,071 INFO L93 rtionOrderModulation]: Changing assertion order to OUTSIDE_LOOP_FIRST2 [2023-03-31 23:07:48,071 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:48,071 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:07:48,072 INFO L229 MonitoredProcess]: Starting monitored process 32 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:07:48,074 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (32)] Waiting until timeout for monitored process [2023-03-31 23:07:48,131 INFO L228 tOrderPrioritization]: Assert order OUTSIDE_LOOP_FIRST2 issued 3 check-sat command(s) [2023-03-31 23:07:48,131 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2023-03-31 23:07:48,132 INFO L262 TraceCheckSpWp]: Trace formula consists of 209 conjuncts, 42 conjunts are in the unsatisfiable core [2023-03-31 23:07:48,132 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:07:48,387 INFO L134 CoverageAnalysis]: Checked inductivity of 26 backedges. 0 proven. 14 refuted. 0 times theorem prover too weak. 12 trivial. 0 not checked. [2023-03-31 23:07:48,387 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-03-31 23:07:48,560 INFO L134 CoverageAnalysis]: Checked inductivity of 26 backedges. 0 proven. 14 refuted. 0 times theorem prover too weak. 12 trivial. 0 not checked. [2023-03-31 23:07:48,561 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1742875694] provided 0 perfect and 2 imperfect interpolant sequences [2023-03-31 23:07:48,561 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [761213457] [2023-03-31 23:07:48,561 INFO L159 IcfgInterpreter]: Started Sifa with 25 locations of interest [2023-03-31 23:07:48,561 INFO L166 IcfgInterpreter]: Building call graph [2023-03-31 23:07:48,562 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2023-03-31 23:07:48,562 INFO L176 IcfgInterpreter]: Starting interpretation [2023-03-31 23:07:48,562 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2023-03-31 23:07:48,569 INFO L197 IcfgInterpreter]: Interpreting procedure main with input of size 8 for LOIs [2023-03-31 23:07:48,621 INFO L197 IcfgInterpreter]: Interpreting procedure __VERIFIER_assert with input of size 26 for LOIs [2023-03-31 23:07:48,626 INFO L197 IcfgInterpreter]: Interpreting procedure student_version with input of size 19 for LOIs [2023-03-31 23:07:48,652 INFO L197 IcfgInterpreter]: Interpreting procedure correct_version with input of size 19 for LOIs [2023-03-31 23:07:48,676 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.init with input of size 7 for LOIs [2023-03-31 23:07:48,678 INFO L180 IcfgInterpreter]: Interpretation finished [2023-03-31 23:07:49,495 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '20387#(and (= |__VERIFIER_assert_#in~cond| 0) (= __VERIFIER_assert_~cond 0) (= |#NULL.offset| 0) (<= 0 |#StackHeapBarrier|) (= |#NULL.base| 0))' at error location [2023-03-31 23:07:49,495 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2023-03-31 23:07:49,495 INFO L185 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2023-03-31 23:07:49,495 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [22, 22, 22] total 32 [2023-03-31 23:07:49,495 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1592634037] [2023-03-31 23:07:49,495 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2023-03-31 23:07:49,496 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 32 states [2023-03-31 23:07:49,496 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:07:49,496 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 32 interpolants. [2023-03-31 23:07:49,496 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=167, Invalid=2695, Unknown=0, NotChecked=0, Total=2862 [2023-03-31 23:07:49,496 INFO L87 Difference]: Start difference. First operand 157 states and 191 transitions. Second operand has 32 states, 27 states have (on average 1.4444444444444444) internal successors, (39), 27 states have internal predecessors, (39), 4 states have call successors, (6), 3 states have call predecessors, (6), 3 states have return successors, (4), 4 states have call predecessors, (4), 2 states have call successors, (4) [2023-03-31 23:07:49,709 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:07:49,709 INFO L93 Difference]: Finished difference Result 171 states and 208 transitions. [2023-03-31 23:07:49,727 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 23 states. [2023-03-31 23:07:49,727 INFO L78 Accepts]: Start accepts. Automaton has has 32 states, 27 states have (on average 1.4444444444444444) internal successors, (39), 27 states have internal predecessors, (39), 4 states have call successors, (6), 3 states have call predecessors, (6), 3 states have return successors, (4), 4 states have call predecessors, (4), 2 states have call successors, (4) Word has length 38 [2023-03-31 23:07:49,728 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:07:49,728 INFO L225 Difference]: With dead ends: 171 [2023-03-31 23:07:49,729 INFO L226 Difference]: Without dead ends: 165 [2023-03-31 23:07:49,729 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 141 GetRequests, 74 SyntacticMatches, 9 SemanticMatches, 58 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 690 ImplicationChecksByTransitivity, 1.3s TimeCoverageRelationStatistics Valid=197, Invalid=3343, Unknown=0, NotChecked=0, Total=3540 [2023-03-31 23:07:49,729 INFO L413 NwaCegarLoop]: 19 mSDtfsCounter, 15 mSDsluCounter, 362 mSDsCounter, 0 mSdLazyCounter, 575 mSolverCounterSat, 1 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.1s Time, 0 mProtectedPredicate, 0 mProtectedAction, 17 SdHoareTripleChecker+Valid, 381 SdHoareTripleChecker+Invalid, 576 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 1 IncrementalHoareTripleChecker+Valid, 575 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.1s IncrementalHoareTripleChecker+Time [2023-03-31 23:07:49,730 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [17 Valid, 381 Invalid, 576 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [1 Valid, 575 Invalid, 0 Unknown, 0 Unchecked, 0.1s Time] [2023-03-31 23:07:49,730 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 165 states. [2023-03-31 23:07:49,772 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 165 to 163. [2023-03-31 23:07:49,772 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 163 states, 127 states have (on average 1.2834645669291338) internal successors, (163), 145 states have internal predecessors, (163), 14 states have call successors, (14), 5 states have call predecessors, (14), 21 states have return successors, (23), 12 states have call predecessors, (23), 12 states have call successors, (23) [2023-03-31 23:07:49,772 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 163 states to 163 states and 200 transitions. [2023-03-31 23:07:49,773 INFO L78 Accepts]: Start accepts. Automaton has 163 states and 200 transitions. Word has length 38 [2023-03-31 23:07:49,773 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:07:49,773 INFO L495 AbstractCegarLoop]: Abstraction has 163 states and 200 transitions. [2023-03-31 23:07:49,773 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 32 states, 27 states have (on average 1.4444444444444444) internal successors, (39), 27 states have internal predecessors, (39), 4 states have call successors, (6), 3 states have call predecessors, (6), 3 states have return successors, (4), 4 states have call predecessors, (4), 2 states have call successors, (4) [2023-03-31 23:07:49,773 INFO L276 IsEmpty]: Start isEmpty. Operand 163 states and 200 transitions. [2023-03-31 23:07:49,774 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 40 [2023-03-31 23:07:49,774 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:07:49,774 INFO L195 NwaCegarLoop]: trace histogram [6, 5, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:07:49,791 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (32)] Forceful destruction successful, exit code 0 [2023-03-31 23:07:49,978 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: 32 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true,SelfDestructingSolverStorable38 [2023-03-31 23:07:49,979 INFO L420 AbstractCegarLoop]: === Iteration 40 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:07:49,979 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:07:49,979 INFO L85 PathProgramCache]: Analyzing trace with hash 851932469, now seen corresponding path program 30 times [2023-03-31 23:07:49,979 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:07:49,979 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [328792592] [2023-03-31 23:07:49,979 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:07:49,979 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:07:49,986 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:50,221 INFO L134 CoverageAnalysis]: Checked inductivity of 40 backedges. 0 proven. 36 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:07:50,222 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:07:50,222 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [328792592] [2023-03-31 23:07:50,222 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [328792592] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:07:50,222 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [622470117] [2023-03-31 23:07:50,222 INFO L93 rtionOrderModulation]: Changing assertion order to TERMS_WITH_SMALL_CONSTANTS_FIRST [2023-03-31 23:07:50,222 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:50,222 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:07:50,223 INFO L229 MonitoredProcess]: Starting monitored process 33 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:07:50,225 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (33)] Waiting until timeout for monitored process [2023-03-31 23:07:50,275 INFO L228 tOrderPrioritization]: Assert order TERMS_WITH_SMALL_CONSTANTS_FIRST issued 0 check-sat command(s) [2023-03-31 23:07:50,275 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2023-03-31 23:07:50,276 INFO L262 TraceCheckSpWp]: Trace formula consists of 165 conjuncts, 22 conjunts are in the unsatisfiable core [2023-03-31 23:07:50,277 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:07:50,549 INFO L134 CoverageAnalysis]: Checked inductivity of 40 backedges. 0 proven. 36 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:07:50,549 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-03-31 23:07:51,017 INFO L134 CoverageAnalysis]: Checked inductivity of 40 backedges. 6 proven. 30 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:07:51,017 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [622470117] provided 0 perfect and 2 imperfect interpolant sequences [2023-03-31 23:07:51,018 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [460683725] [2023-03-31 23:07:51,018 INFO L159 IcfgInterpreter]: Started Sifa with 25 locations of interest [2023-03-31 23:07:51,018 INFO L166 IcfgInterpreter]: Building call graph [2023-03-31 23:07:51,018 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2023-03-31 23:07:51,019 INFO L176 IcfgInterpreter]: Starting interpretation [2023-03-31 23:07:51,019 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2023-03-31 23:07:51,026 INFO L197 IcfgInterpreter]: Interpreting procedure main with input of size 8 for LOIs [2023-03-31 23:07:51,083 INFO L197 IcfgInterpreter]: Interpreting procedure __VERIFIER_assert with input of size 26 for LOIs [2023-03-31 23:07:51,089 INFO L197 IcfgInterpreter]: Interpreting procedure student_version with input of size 19 for LOIs [2023-03-31 23:07:51,113 INFO L197 IcfgInterpreter]: Interpreting procedure correct_version with input of size 19 for LOIs [2023-03-31 23:07:51,136 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.init with input of size 7 for LOIs [2023-03-31 23:07:51,138 INFO L180 IcfgInterpreter]: Interpretation finished [2023-03-31 23:07:52,372 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '21284#(and (= |__VERIFIER_assert_#in~cond| 0) (= __VERIFIER_assert_~cond 0) (= |#NULL.offset| 0) (<= 0 |#StackHeapBarrier|) (= |#NULL.base| 0))' at error location [2023-03-31 23:07:52,372 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2023-03-31 23:07:52,373 INFO L185 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2023-03-31 23:07:52,373 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [17, 17, 17] total 41 [2023-03-31 23:07:52,373 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [361067963] [2023-03-31 23:07:52,373 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2023-03-31 23:07:52,373 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 41 states [2023-03-31 23:07:52,373 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:07:52,374 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 41 interpolants. [2023-03-31 23:07:52,374 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=203, Invalid=3703, Unknown=0, NotChecked=0, Total=3906 [2023-03-31 23:07:52,374 INFO L87 Difference]: Start difference. First operand 163 states and 200 transitions. Second operand has 41 states, 41 states have (on average 1.6341463414634145) internal successors, (67), 41 states have internal predecessors, (67), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:07:53,656 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:07:53,657 INFO L93 Difference]: Finished difference Result 197 states and 243 transitions. [2023-03-31 23:07:53,657 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 25 states. [2023-03-31 23:07:53,657 INFO L78 Accepts]: Start accepts. Automaton has has 41 states, 41 states have (on average 1.6341463414634145) internal successors, (67), 41 states have internal predecessors, (67), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) Word has length 39 [2023-03-31 23:07:53,657 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:07:53,658 INFO L225 Difference]: With dead ends: 197 [2023-03-31 23:07:53,658 INFO L226 Difference]: Without dead ends: 186 [2023-03-31 23:07:53,659 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 151 GetRequests, 69 SyntacticMatches, 3 SemanticMatches, 79 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 1047 ImplicationChecksByTransitivity, 2.5s TimeCoverageRelationStatistics Valid=376, Invalid=6104, Unknown=0, NotChecked=0, Total=6480 [2023-03-31 23:07:53,659 INFO L413 NwaCegarLoop]: 27 mSDtfsCounter, 123 mSDsluCounter, 620 mSDsCounter, 0 mSdLazyCounter, 1396 mSolverCounterSat, 19 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.5s Time, 0 mProtectedPredicate, 0 mProtectedAction, 128 SdHoareTripleChecker+Valid, 647 SdHoareTripleChecker+Invalid, 1415 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 19 IncrementalHoareTripleChecker+Valid, 1396 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.6s IncrementalHoareTripleChecker+Time [2023-03-31 23:07:53,660 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [128 Valid, 647 Invalid, 1415 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [19 Valid, 1396 Invalid, 0 Unknown, 0 Unchecked, 0.6s Time] [2023-03-31 23:07:53,660 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 186 states. [2023-03-31 23:07:53,712 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 186 to 180. [2023-03-31 23:07:53,713 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 180 states, 141 states have (on average 1.2836879432624113) internal successors, (181), 161 states have internal predecessors, (181), 15 states have call successors, (15), 5 states have call predecessors, (15), 23 states have return successors, (26), 13 states have call predecessors, (26), 13 states have call successors, (26) [2023-03-31 23:07:53,713 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 180 states to 180 states and 222 transitions. [2023-03-31 23:07:53,713 INFO L78 Accepts]: Start accepts. Automaton has 180 states and 222 transitions. Word has length 39 [2023-03-31 23:07:53,714 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:07:53,714 INFO L495 AbstractCegarLoop]: Abstraction has 180 states and 222 transitions. [2023-03-31 23:07:53,714 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 41 states, 41 states have (on average 1.6341463414634145) internal successors, (67), 41 states have internal predecessors, (67), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:07:53,714 INFO L276 IsEmpty]: Start isEmpty. Operand 180 states and 222 transitions. [2023-03-31 23:07:53,715 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 40 [2023-03-31 23:07:53,715 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:07:53,715 INFO L195 NwaCegarLoop]: trace histogram [6, 5, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:07:53,735 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (33)] Forceful destruction successful, exit code 0 [2023-03-31 23:07:53,919 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: 33 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true,SelfDestructingSolverStorable39 [2023-03-31 23:07:53,919 INFO L420 AbstractCegarLoop]: === Iteration 41 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:07:53,919 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:07:53,919 INFO L85 PathProgramCache]: Analyzing trace with hash 1701215780, now seen corresponding path program 31 times [2023-03-31 23:07:53,919 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:07:53,919 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [988548006] [2023-03-31 23:07:53,920 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:07:53,920 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:07:53,926 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:54,113 INFO L134 CoverageAnalysis]: Checked inductivity of 40 backedges. 0 proven. 36 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:07:54,113 INFO L136 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2023-03-31 23:07:54,113 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [988548006] [2023-03-31 23:07:54,113 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [988548006] provided 0 perfect and 1 imperfect interpolant sequences [2023-03-31 23:07:54,113 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1219106678] [2023-03-31 23:07:54,113 INFO L93 rtionOrderModulation]: Changing assertion order to NOT_INCREMENTALLY [2023-03-31 23:07:54,113 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-03-31 23:07:54,113 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-03-31 23:07:54,129 INFO L229 MonitoredProcess]: Starting monitored process 34 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-03-31 23:07:54,181 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (34)] Waiting until timeout for monitored process [2023-03-31 23:07:54,217 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-03-31 23:07:54,223 INFO L262 TraceCheckSpWp]: Trace formula consists of 214 conjuncts, 22 conjunts are in the unsatisfiable core [2023-03-31 23:07:54,225 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-03-31 23:07:54,570 INFO L134 CoverageAnalysis]: Checked inductivity of 40 backedges. 0 proven. 36 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:07:54,570 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-03-31 23:07:55,063 INFO L134 CoverageAnalysis]: Checked inductivity of 40 backedges. 6 proven. 30 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2023-03-31 23:07:55,063 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1219106678] provided 0 perfect and 2 imperfect interpolant sequences [2023-03-31 23:07:55,063 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [1954730649] [2023-03-31 23:07:55,064 INFO L159 IcfgInterpreter]: Started Sifa with 25 locations of interest [2023-03-31 23:07:55,064 INFO L166 IcfgInterpreter]: Building call graph [2023-03-31 23:07:55,064 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2023-03-31 23:07:55,064 INFO L176 IcfgInterpreter]: Starting interpretation [2023-03-31 23:07:55,065 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2023-03-31 23:07:55,072 INFO L197 IcfgInterpreter]: Interpreting procedure main with input of size 8 for LOIs [2023-03-31 23:07:55,123 INFO L197 IcfgInterpreter]: Interpreting procedure __VERIFIER_assert with input of size 26 for LOIs [2023-03-31 23:07:55,129 INFO L197 IcfgInterpreter]: Interpreting procedure student_version with input of size 19 for LOIs [2023-03-31 23:07:55,153 INFO L197 IcfgInterpreter]: Interpreting procedure correct_version with input of size 19 for LOIs [2023-03-31 23:07:55,178 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.init with input of size 7 for LOIs [2023-03-31 23:07:55,180 INFO L180 IcfgInterpreter]: Interpretation finished [2023-03-31 23:07:56,221 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '22282#(and (= |__VERIFIER_assert_#in~cond| 0) (= __VERIFIER_assert_~cond 0) (= |#NULL.offset| 0) (<= 0 |#StackHeapBarrier|) (= |#NULL.base| 0))' at error location [2023-03-31 23:07:56,221 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2023-03-31 23:07:56,221 INFO L185 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2023-03-31 23:07:56,221 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [17, 17, 17] total 41 [2023-03-31 23:07:56,221 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1493841392] [2023-03-31 23:07:56,221 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2023-03-31 23:07:56,222 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 41 states [2023-03-31 23:07:56,222 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2023-03-31 23:07:56,222 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 41 interpolants. [2023-03-31 23:07:56,222 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=210, Invalid=3696, Unknown=0, NotChecked=0, Total=3906 [2023-03-31 23:07:56,222 INFO L87 Difference]: Start difference. First operand 180 states and 222 transitions. Second operand has 41 states, 41 states have (on average 1.6341463414634145) internal successors, (67), 41 states have internal predecessors, (67), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:07:57,127 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-03-31 23:07:57,127 INFO L93 Difference]: Finished difference Result 192 states and 234 transitions. [2023-03-31 23:07:57,127 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 26 states. [2023-03-31 23:07:57,127 INFO L78 Accepts]: Start accepts. Automaton has has 41 states, 41 states have (on average 1.6341463414634145) internal successors, (67), 41 states have internal predecessors, (67), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) Word has length 39 [2023-03-31 23:07:57,127 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-03-31 23:07:57,128 INFO L225 Difference]: With dead ends: 192 [2023-03-31 23:07:57,128 INFO L226 Difference]: Without dead ends: 183 [2023-03-31 23:07:57,129 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 154 GetRequests, 69 SyntacticMatches, 3 SemanticMatches, 82 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 1622 ImplicationChecksByTransitivity, 2.2s TimeCoverageRelationStatistics Valid=403, Invalid=6569, Unknown=0, NotChecked=0, Total=6972 [2023-03-31 23:07:57,129 INFO L413 NwaCegarLoop]: 32 mSDtfsCounter, 107 mSDsluCounter, 733 mSDsCounter, 0 mSdLazyCounter, 1396 mSolverCounterSat, 20 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.3s Time, 0 mProtectedPredicate, 0 mProtectedAction, 108 SdHoareTripleChecker+Valid, 765 SdHoareTripleChecker+Invalid, 1416 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 20 IncrementalHoareTripleChecker+Valid, 1396 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.4s IncrementalHoareTripleChecker+Time [2023-03-31 23:07:57,129 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [108 Valid, 765 Invalid, 1416 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [20 Valid, 1396 Invalid, 0 Unknown, 0 Unchecked, 0.4s Time] [2023-03-31 23:07:57,133 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 183 states. [2023-03-31 23:07:57,190 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 183 to 181. [2023-03-31 23:07:57,190 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 181 states, 142 states have (on average 1.2816901408450705) internal successors, (182), 162 states have internal predecessors, (182), 15 states have call successors, (15), 5 states have call predecessors, (15), 23 states have return successors, (24), 13 states have call predecessors, (24), 13 states have call successors, (24) [2023-03-31 23:07:57,191 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 181 states to 181 states and 221 transitions. [2023-03-31 23:07:57,191 INFO L78 Accepts]: Start accepts. Automaton has 181 states and 221 transitions. Word has length 39 [2023-03-31 23:07:57,191 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-03-31 23:07:57,191 INFO L495 AbstractCegarLoop]: Abstraction has 181 states and 221 transitions. [2023-03-31 23:07:57,191 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 41 states, 41 states have (on average 1.6341463414634145) internal successors, (67), 41 states have internal predecessors, (67), 3 states have call successors, (5), 2 states have call predecessors, (5), 3 states have return successors, (3), 3 states have call predecessors, (3), 2 states have call successors, (3) [2023-03-31 23:07:57,192 INFO L276 IsEmpty]: Start isEmpty. Operand 181 states and 221 transitions. [2023-03-31 23:07:57,192 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 40 [2023-03-31 23:07:57,192 INFO L187 NwaCegarLoop]: Found error trace [2023-03-31 23:07:57,193 INFO L195 NwaCegarLoop]: trace histogram [4, 3, 3, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-03-31 23:07:57,197 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (34)] Forceful destruction successful, exit code 0 [2023-03-31 23:07:57,397 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: 34 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true,SelfDestructingSolverStorable40 [2023-03-31 23:07:57,397 INFO L420 AbstractCegarLoop]: === Iteration 42 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-03-31 23:07:57,397 INFO L145 PredicateUnifier]: Initialized classic predicate unifier [2023-03-31 23:07:57,398 INFO L85 PathProgramCache]: Analyzing trace with hash 1422988524, now seen corresponding path program 32 times [2023-03-31 23:07:57,398 INFO L118 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2023-03-31 23:07:57,398 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [923199577] [2023-03-31 23:07:57,398 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-03-31 23:07:57,398 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-03-31 23:07:57,413 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat