./Ultimate.py --spec ../../sv-benchmarks/c/properties/unreach-call.prp --file ../../sv-benchmarks/c/loops-crafted-1/watermelon.c --full-output --architecture 32bit -------------------------------------------------------------------------------- Checking for ERROR reachability Using default analysis Version aef121e0 Calling Ultimate with: /usr/bin/java -Dosgi.configuration.area=/tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/data/config -Xmx15G -Xms4m -jar /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/plugins/org.eclipse.equinox.launcher_1.5.800.v20200727-1323.jar -data @noDefault -ultimatedata /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/data -tc /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/config/TaipanReach.xml -i ../../sv-benchmarks/c/loops-crafted-1/watermelon.c -s /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/config/svcomp-Reach-32bit-Taipan_Default.epf --cacsl2boogietranslator.entry.function main --witnessprinter.witness.directory /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V --witnessprinter.witness.filename witness.graphml --witnessprinter.write.witness.besides.input.file false --witnessprinter.graph.data.specification CHECK( init(main()), LTL(G ! call(reach_error())) ) --witnessprinter.graph.data.producer Taipan --witnessprinter.graph.data.architecture 32bit --witnessprinter.graph.data.programhash dda0b992ac1600896503297d86377b482d0a82ded923ea00c7e9ff3fed4db7e7 --- Real Ultimate output --- This is Ultimate 0.2.1-dev-aef121e [2021-11-23 03:30:13,301 INFO L177 SettingsManager]: Resetting all preferences to default values... [2021-11-23 03:30:13,303 INFO L181 SettingsManager]: Resetting UltimateCore preferences to default values [2021-11-23 03:30:13,341 INFO L184 SettingsManager]: Ultimate Commandline Interface provides no preferences, ignoring... [2021-11-23 03:30:13,342 INFO L181 SettingsManager]: Resetting Boogie Preprocessor preferences to default values [2021-11-23 03:30:13,343 INFO L181 SettingsManager]: Resetting Boogie Procedure Inliner preferences to default values [2021-11-23 03:30:13,346 INFO L181 SettingsManager]: Resetting Abstract Interpretation preferences to default values [2021-11-23 03:30:13,348 INFO L181 SettingsManager]: Resetting LassoRanker preferences to default values [2021-11-23 03:30:13,351 INFO L181 SettingsManager]: Resetting Reaching Definitions preferences to default values [2021-11-23 03:30:13,353 INFO L181 SettingsManager]: Resetting SyntaxChecker preferences to default values [2021-11-23 03:30:13,354 INFO L181 SettingsManager]: Resetting Sifa preferences to default values [2021-11-23 03:30:13,356 INFO L184 SettingsManager]: Büchi Program Product provides no preferences, ignoring... [2021-11-23 03:30:13,357 INFO L181 SettingsManager]: Resetting LTL2Aut preferences to default values [2021-11-23 03:30:13,359 INFO L181 SettingsManager]: Resetting PEA to Boogie preferences to default values [2021-11-23 03:30:13,361 INFO L181 SettingsManager]: Resetting BlockEncodingV2 preferences to default values [2021-11-23 03:30:13,363 INFO L181 SettingsManager]: Resetting ChcToBoogie preferences to default values [2021-11-23 03:30:13,365 INFO L181 SettingsManager]: Resetting AutomataScriptInterpreter preferences to default values [2021-11-23 03:30:13,366 INFO L181 SettingsManager]: Resetting BuchiAutomizer preferences to default values [2021-11-23 03:30:13,370 INFO L181 SettingsManager]: Resetting CACSL2BoogieTranslator preferences to default values [2021-11-23 03:30:13,373 INFO L181 SettingsManager]: Resetting CodeCheck preferences to default values [2021-11-23 03:30:13,376 INFO L181 SettingsManager]: Resetting InvariantSynthesis preferences to default values [2021-11-23 03:30:13,378 INFO L181 SettingsManager]: Resetting RCFGBuilder preferences to default values [2021-11-23 03:30:13,380 INFO L181 SettingsManager]: Resetting Referee preferences to default values [2021-11-23 03:30:13,381 INFO L181 SettingsManager]: Resetting TraceAbstraction preferences to default values [2021-11-23 03:30:13,387 INFO L184 SettingsManager]: TraceAbstractionConcurrent provides no preferences, ignoring... [2021-11-23 03:30:13,397 INFO L184 SettingsManager]: TraceAbstractionWithAFAs provides no preferences, ignoring... [2021-11-23 03:30:13,397 INFO L181 SettingsManager]: Resetting TreeAutomizer preferences to default values [2021-11-23 03:30:13,399 INFO L181 SettingsManager]: Resetting IcfgToChc preferences to default values [2021-11-23 03:30:13,400 INFO L181 SettingsManager]: Resetting IcfgTransformer preferences to default values [2021-11-23 03:30:13,401 INFO L184 SettingsManager]: ReqToTest provides no preferences, ignoring... [2021-11-23 03:30:13,403 INFO L181 SettingsManager]: Resetting Boogie Printer preferences to default values [2021-11-23 03:30:13,404 INFO L181 SettingsManager]: Resetting ChcSmtPrinter preferences to default values [2021-11-23 03:30:13,405 INFO L181 SettingsManager]: Resetting ReqPrinter preferences to default values [2021-11-23 03:30:13,406 INFO L181 SettingsManager]: Resetting Witness Printer preferences to default values [2021-11-23 03:30:13,407 INFO L184 SettingsManager]: Boogie PL CUP Parser provides no preferences, ignoring... [2021-11-23 03:30:13,407 INFO L181 SettingsManager]: Resetting CDTParser preferences to default values [2021-11-23 03:30:13,408 INFO L184 SettingsManager]: AutomataScriptParser provides no preferences, ignoring... [2021-11-23 03:30:13,408 INFO L184 SettingsManager]: ReqParser provides no preferences, ignoring... [2021-11-23 03:30:13,408 INFO L181 SettingsManager]: Resetting SmtParser preferences to default values [2021-11-23 03:30:13,409 INFO L181 SettingsManager]: Resetting Witness Parser preferences to default values [2021-11-23 03:30:13,410 INFO L188 SettingsManager]: Finished resetting all preferences to default values... [2021-11-23 03:30:13,411 INFO L101 SettingsManager]: Beginning loading settings from /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/config/svcomp-Reach-32bit-Taipan_Default.epf [2021-11-23 03:30:13,443 INFO L113 SettingsManager]: Loading preferences was successful [2021-11-23 03:30:13,443 INFO L115 SettingsManager]: Preferences different from defaults after loading the file: [2021-11-23 03:30:13,443 INFO L136 SettingsManager]: Preferences of UltimateCore differ from their defaults: [2021-11-23 03:30:13,444 INFO L138 SettingsManager]: * Log level for class=de.uni_freiburg.informatik.ultimate.lib.smtlibutils.quantifier.QuantifierPusher=ERROR; [2021-11-23 03:30:13,444 INFO L136 SettingsManager]: Preferences of Boogie Procedure Inliner differ from their defaults: [2021-11-23 03:30:13,445 INFO L138 SettingsManager]: * Ignore calls to procedures called more than once=ONLY_FOR_SEQUENTIAL_PROGRAMS [2021-11-23 03:30:13,445 INFO L138 SettingsManager]: * User list type=DISABLED [2021-11-23 03:30:13,445 INFO L136 SettingsManager]: Preferences of Abstract Interpretation differ from their defaults: [2021-11-23 03:30:13,446 INFO L138 SettingsManager]: * Explicit value domain=true [2021-11-23 03:30:13,446 INFO L138 SettingsManager]: * Abstract domain for RCFG-of-the-future=PoormanAbstractDomain [2021-11-23 03:30:13,446 INFO L138 SettingsManager]: * Octagon Domain=false [2021-11-23 03:30:13,446 INFO L138 SettingsManager]: * Abstract domain=CompoundDomain [2021-11-23 03:30:13,447 INFO L138 SettingsManager]: * Check feasibility of abstract posts with an SMT solver=true [2021-11-23 03:30:13,447 INFO L138 SettingsManager]: * Use the RCFG-of-the-future interface=true [2021-11-23 03:30:13,447 INFO L138 SettingsManager]: * Interval Domain=false [2021-11-23 03:30:13,447 INFO L136 SettingsManager]: Preferences of Sifa differ from their defaults: [2021-11-23 03:30:13,448 INFO L138 SettingsManager]: * Call Summarizer=TopInputCallSummarizer [2021-11-23 03:30:13,448 INFO L138 SettingsManager]: * Simplification Technique=POLY_PAC [2021-11-23 03:30:13,449 INFO L136 SettingsManager]: Preferences of CACSL2BoogieTranslator differ from their defaults: [2021-11-23 03:30:13,449 INFO L138 SettingsManager]: * sizeof long=4 [2021-11-23 03:30:13,449 INFO L138 SettingsManager]: * Overapproximate operations on floating types=true [2021-11-23 03:30:13,450 INFO L138 SettingsManager]: * sizeof POINTER=4 [2021-11-23 03:30:13,450 INFO L138 SettingsManager]: * Check division by zero=IGNORE [2021-11-23 03:30:13,450 INFO L138 SettingsManager]: * Pointer to allocated memory at dereference=IGNORE [2021-11-23 03:30:13,450 INFO L138 SettingsManager]: * If two pointers are subtracted or compared they have the same base address=IGNORE [2021-11-23 03:30:13,451 INFO L138 SettingsManager]: * Check array bounds for arrays that are off heap=IGNORE [2021-11-23 03:30:13,451 INFO L138 SettingsManager]: * sizeof long double=12 [2021-11-23 03:30:13,451 INFO L138 SettingsManager]: * Check if freed pointer was valid=false [2021-11-23 03:30:13,451 INFO L138 SettingsManager]: * Use constant arrays=true [2021-11-23 03:30:13,452 INFO L138 SettingsManager]: * Pointer base address is valid at dereference=IGNORE [2021-11-23 03:30:13,452 INFO L136 SettingsManager]: Preferences of RCFGBuilder differ from their defaults: [2021-11-23 03:30:13,452 INFO L138 SettingsManager]: * SMT solver=External_DefaultMode [2021-11-23 03:30:13,452 INFO L138 SettingsManager]: * Command for external solver=z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in -t:2000 [2021-11-23 03:30:13,453 INFO L136 SettingsManager]: Preferences of TraceAbstraction differ from their defaults: [2021-11-23 03:30:13,453 INFO L138 SettingsManager]: * Compute Interpolants along a Counterexample=FPandBP [2021-11-23 03:30:13,453 INFO L138 SettingsManager]: * Positions where we compute the Hoare Annotation=LoopsAndPotentialCycles [2021-11-23 03:30:13,454 INFO L138 SettingsManager]: * Trace refinement strategy=SIFA_TAIPAN [2021-11-23 03:30:13,454 INFO L138 SettingsManager]: * Command for external solver=z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in [2021-11-23 03:30:13,454 INFO L138 SettingsManager]: * Compute Hoare Annotation of negated interpolant automaton, abstraction and CFG=true [2021-11-23 03:30:13,454 INFO L138 SettingsManager]: * Trace refinement exception blacklist=NONE [2021-11-23 03:30:13,455 INFO L138 SettingsManager]: * SMT solver=External_ModelsAndUnsatCoreMode [2021-11-23 03:30:13,455 INFO L138 SettingsManager]: * Abstract interpretation Mode=USE_PREDICATES WARNING: An illegal reflective access operation has occurred WARNING: Illegal reflective access by com.sun.xml.bind.v2.runtime.reflect.opt.Injector$1 (file:/tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/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$1 WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations WARNING: All illegal access operations will be denied in a future release Applying setting for plugin de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator: Entry function -> main Applying setting for plugin de.uni_freiburg.informatik.ultimate.witnessprinter: Witness directory -> /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V Applying setting for plugin de.uni_freiburg.informatik.ultimate.witnessprinter: Witness filename -> witness.graphml Applying setting for plugin de.uni_freiburg.informatik.ultimate.witnessprinter: Write witness besides input file -> false Applying setting for plugin de.uni_freiburg.informatik.ultimate.witnessprinter: Graph data specification -> CHECK( init(main()), LTL(G ! call(reach_error())) ) Applying setting for plugin de.uni_freiburg.informatik.ultimate.witnessprinter: Graph data producer -> Taipan Applying setting for plugin de.uni_freiburg.informatik.ultimate.witnessprinter: Graph data architecture -> 32bit Applying setting for plugin de.uni_freiburg.informatik.ultimate.witnessprinter: Graph data programhash -> dda0b992ac1600896503297d86377b482d0a82ded923ea00c7e9ff3fed4db7e7 [2021-11-23 03:30:13,714 INFO L75 nceAwareModelManager]: Repository-Root is: /tmp [2021-11-23 03:30:13,740 INFO L261 ainManager$Toolchain]: [Toolchain 1]: Applicable parser(s) successfully (re)initialized [2021-11-23 03:30:13,743 INFO L217 ainManager$Toolchain]: [Toolchain 1]: Toolchain selected. [2021-11-23 03:30:13,744 INFO L271 PluginConnector]: Initializing CDTParser... [2021-11-23 03:30:13,745 INFO L275 PluginConnector]: CDTParser initialized [2021-11-23 03:30:13,746 INFO L432 ainManager$Toolchain]: [Toolchain 1]: Parsing single file: /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/../../sv-benchmarks/c/loops-crafted-1/watermelon.c [2021-11-23 03:30:13,833 INFO L220 CDTParser]: Created temporary CDT project at /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/data/bc2b61a20/8ccdf896417644ba8909e05ef70b5abf/FLAG87554d863 [2021-11-23 03:30:14,418 INFO L306 CDTParser]: Found 1 translation units. [2021-11-23 03:30:14,419 INFO L160 CDTParser]: Scanning /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/sv-benchmarks/c/loops-crafted-1/watermelon.c [2021-11-23 03:30:14,432 INFO L349 CDTParser]: About to delete temporary CDT project at /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/data/bc2b61a20/8ccdf896417644ba8909e05ef70b5abf/FLAG87554d863 [2021-11-23 03:30:14,760 INFO L357 CDTParser]: Successfully deleted /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/data/bc2b61a20/8ccdf896417644ba8909e05ef70b5abf [2021-11-23 03:30:14,763 INFO L299 ainManager$Toolchain]: ####################### [Toolchain 1] ####################### [2021-11-23 03:30:14,765 INFO L131 ToolchainWalker]: Walking toolchain with 6 elements. [2021-11-23 03:30:14,767 INFO L113 PluginConnector]: ------------------------CACSL2BoogieTranslator---------------------------- [2021-11-23 03:30:14,767 INFO L271 PluginConnector]: Initializing CACSL2BoogieTranslator... [2021-11-23 03:30:14,774 INFO L275 PluginConnector]: CACSL2BoogieTranslator initialized [2021-11-23 03:30:14,775 INFO L185 PluginConnector]: Executing the observer ACSLObjectContainerObserver from plugin CACSL2BoogieTranslator for "CDTParser AST 23.11 03:30:14" (1/1) ... [2021-11-23 03:30:14,776 INFO L205 PluginConnector]: Invalid model from CACSL2BoogieTranslator for observer de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator.ACSLObjectContainerObserver@352d78a4 and model type de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 23.11 03:30:14, skipping insertion in model container [2021-11-23 03:30:14,777 INFO L185 PluginConnector]: Executing the observer CACSL2BoogieTranslatorObserver from plugin CACSL2BoogieTranslator for "CDTParser AST 23.11 03:30:14" (1/1) ... [2021-11-23 03:30:14,786 INFO L145 MainTranslator]: Starting translation in SV-COMP mode [2021-11-23 03:30:14,804 INFO L178 MainTranslator]: Built tables and reachable declarations [2021-11-23 03:30:15,044 WARN L230 ndardFunctionHandler]: Function reach_error is already implemented but we override the implementation for the call at /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/sv-benchmarks/c/loops-crafted-1/watermelon.c[373,386] [2021-11-23 03:30:15,063 INFO L209 PostProcessor]: Analyzing one entry point: main [2021-11-23 03:30:15,072 INFO L203 MainTranslator]: Completed pre-run [2021-11-23 03:30:15,085 WARN L230 ndardFunctionHandler]: Function reach_error is already implemented but we override the implementation for the call at /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/sv-benchmarks/c/loops-crafted-1/watermelon.c[373,386] [2021-11-23 03:30:15,093 INFO L209 PostProcessor]: Analyzing one entry point: main [2021-11-23 03:30:15,108 INFO L208 MainTranslator]: Completed translation [2021-11-23 03:30:15,108 INFO L202 PluginConnector]: Adding new model de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 23.11 03:30:15 WrapperNode [2021-11-23 03:30:15,109 INFO L132 PluginConnector]: ------------------------ END CACSL2BoogieTranslator---------------------------- [2021-11-23 03:30:15,110 INFO L113 PluginConnector]: ------------------------Boogie Procedure Inliner---------------------------- [2021-11-23 03:30:15,110 INFO L271 PluginConnector]: Initializing Boogie Procedure Inliner... [2021-11-23 03:30:15,110 INFO L275 PluginConnector]: Boogie Procedure Inliner initialized [2021-11-23 03:30:15,119 INFO L185 PluginConnector]: Executing the observer TypeChecker from plugin Boogie Procedure Inliner for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 23.11 03:30:15" (1/1) ... [2021-11-23 03:30:15,126 INFO L185 PluginConnector]: Executing the observer Inliner from plugin Boogie Procedure Inliner for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 23.11 03:30:15" (1/1) ... [2021-11-23 03:30:15,149 INFO L137 Inliner]: procedures = 15, calls = 10, calls flagged for inlining = 5, calls inlined = 5, statements flattened = 64 [2021-11-23 03:30:15,149 INFO L132 PluginConnector]: ------------------------ END Boogie Procedure Inliner---------------------------- [2021-11-23 03:30:15,150 INFO L113 PluginConnector]: ------------------------Boogie Preprocessor---------------------------- [2021-11-23 03:30:15,150 INFO L271 PluginConnector]: Initializing Boogie Preprocessor... [2021-11-23 03:30:15,151 INFO L275 PluginConnector]: Boogie Preprocessor initialized [2021-11-23 03:30:15,161 INFO L185 PluginConnector]: Executing the observer EnsureBoogieModelObserver from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 23.11 03:30:15" (1/1) ... [2021-11-23 03:30:15,161 INFO L185 PluginConnector]: Executing the observer TypeChecker from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 23.11 03:30:15" (1/1) ... [2021-11-23 03:30:15,163 INFO L185 PluginConnector]: Executing the observer ConstExpander from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 23.11 03:30:15" (1/1) ... [2021-11-23 03:30:15,163 INFO L185 PluginConnector]: Executing the observer StructExpander from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 23.11 03:30:15" (1/1) ... [2021-11-23 03:30:15,167 INFO L185 PluginConnector]: Executing the observer UnstructureCode from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 23.11 03:30:15" (1/1) ... [2021-11-23 03:30:15,172 INFO L185 PluginConnector]: Executing the observer FunctionInliner from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 23.11 03:30:15" (1/1) ... [2021-11-23 03:30:15,174 INFO L185 PluginConnector]: Executing the observer BoogieSymbolTableConstructor from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 23.11 03:30:15" (1/1) ... [2021-11-23 03:30:15,176 INFO L132 PluginConnector]: ------------------------ END Boogie Preprocessor---------------------------- [2021-11-23 03:30:15,177 INFO L113 PluginConnector]: ------------------------RCFGBuilder---------------------------- [2021-11-23 03:30:15,178 INFO L271 PluginConnector]: Initializing RCFGBuilder... [2021-11-23 03:30:15,178 INFO L275 PluginConnector]: RCFGBuilder initialized [2021-11-23 03:30:15,182 INFO L185 PluginConnector]: Executing the observer RCFGBuilderObserver from plugin RCFGBuilder for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 23.11 03:30:15" (1/1) ... [2021-11-23 03:30:15,193 INFO L168 SolverBuilder]: Constructing external solver with command: z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in -t:2000 [2021-11-23 03:30:15,207 INFO L189 MonitoredProcess]: No working directory specified, using /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 [2021-11-23 03:30:15,239 INFO L229 MonitoredProcess]: Starting monitored process 1 with /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in -t:2000 (exit command is (exit), workingDir is null) [2021-11-23 03:30:15,261 INFO L327 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in -t:2000 (1)] Waiting until timeout for monitored process [2021-11-23 03:30:15,299 INFO L130 BoogieDeclarations]: Found specification of procedure #Ultimate.allocInit [2021-11-23 03:30:15,299 INFO L130 BoogieDeclarations]: Found specification of procedure write~init~int [2021-11-23 03:30:15,300 INFO L130 BoogieDeclarations]: Found specification of procedure ULTIMATE.start [2021-11-23 03:30:15,300 INFO L138 BoogieDeclarations]: Found implementation of procedure ULTIMATE.start [2021-11-23 03:30:15,367 INFO L236 CfgBuilder]: Building ICFG [2021-11-23 03:30:15,369 INFO L262 CfgBuilder]: Building CFG for each procedure with an implementation [2021-11-23 03:30:15,562 INFO L277 CfgBuilder]: Performing block encoding [2021-11-23 03:30:15,617 INFO L296 CfgBuilder]: Using the 1 location(s) as analysis (start of procedure ULTIMATE.start) [2021-11-23 03:30:15,618 INFO L301 CfgBuilder]: Removed 2 assume(true) statements. [2021-11-23 03:30:15,620 INFO L202 PluginConnector]: Adding new model de.uni_freiburg.informatik.ultimate.plugins.generator.rcfgbuilder CFG 23.11 03:30:15 BoogieIcfgContainer [2021-11-23 03:30:15,621 INFO L132 PluginConnector]: ------------------------ END RCFGBuilder---------------------------- [2021-11-23 03:30:15,622 INFO L113 PluginConnector]: ------------------------TraceAbstraction---------------------------- [2021-11-23 03:30:15,637 INFO L271 PluginConnector]: Initializing TraceAbstraction... [2021-11-23 03:30:15,641 INFO L275 PluginConnector]: TraceAbstraction initialized [2021-11-23 03:30:15,641 INFO L185 PluginConnector]: Executing the observer TraceAbstractionObserver from plugin TraceAbstraction for "CDTParser AST 23.11 03:30:14" (1/3) ... [2021-11-23 03:30:15,642 INFO L205 PluginConnector]: Invalid model from TraceAbstraction for observer de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction.TraceAbstractionObserver@1b38949c and model type de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction AST 23.11 03:30:15, skipping insertion in model container [2021-11-23 03:30:15,642 INFO L185 PluginConnector]: Executing the observer TraceAbstractionObserver from plugin TraceAbstraction for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 23.11 03:30:15" (2/3) ... [2021-11-23 03:30:15,643 INFO L205 PluginConnector]: Invalid model from TraceAbstraction for observer de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction.TraceAbstractionObserver@1b38949c and model type de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction AST 23.11 03:30:15, skipping insertion in model container [2021-11-23 03:30:15,643 INFO L185 PluginConnector]: Executing the observer TraceAbstractionObserver from plugin TraceAbstraction for "de.uni_freiburg.informatik.ultimate.plugins.generator.rcfgbuilder CFG 23.11 03:30:15" (3/3) ... [2021-11-23 03:30:15,644 INFO L111 eAbstractionObserver]: Analyzing ICFG watermelon.c [2021-11-23 03:30:15,650 INFO L204 ceAbstractionStarter]: Automizer settings: Hoare:true NWA Interpolation:FPandBP Determinization: PREDICATE_ABSTRACTION [2021-11-23 03:30:15,650 INFO L163 ceAbstractionStarter]: Applying trace abstraction to program that has 1 error locations. [2021-11-23 03:30:15,716 INFO L338 AbstractCegarLoop]: ======== Iteration 0 == of CEGAR loop == AllErrorsAtOnce ======== [2021-11-23 03:30:15,723 INFO L339 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, mLoopAccelerationTechnique=FAST_UPR [2021-11-23 03:30:15,724 INFO L340 AbstractCegarLoop]: Starting to check reachability of 1 error locations. [2021-11-23 03:30:15,738 INFO L276 IsEmpty]: Start isEmpty. Operand has 14 states, 12 states have (on average 1.5833333333333333) internal successors, (19), 13 states have internal predecessors, (19), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:15,743 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 9 [2021-11-23 03:30:15,743 INFO L506 BasicCegarLoop]: Found error trace [2021-11-23 03:30:15,744 INFO L514 BasicCegarLoop]: trace histogram [1, 1, 1, 1, 1, 1, 1, 1] [2021-11-23 03:30:15,744 INFO L402 AbstractCegarLoop]: === Iteration 1 === Targeting ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION === [ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2021-11-23 03:30:15,751 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2021-11-23 03:30:15,751 INFO L85 PathProgramCache]: Analyzing trace with hash -1927148626, now seen corresponding path program 1 times [2021-11-23 03:30:15,761 INFO L121 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2021-11-23 03:30:15,766 INFO L333 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [119423863] [2021-11-23 03:30:15,766 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:30:15,767 INFO L126 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2021-11-23 03:30:15,914 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:30:16,083 INFO L134 CoverageAnalysis]: Checked inductivity of 0 backedges. 0 proven. 0 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:30:16,084 INFO L139 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2021-11-23 03:30:16,084 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [119423863] [2021-11-23 03:30:16,085 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [119423863] provided 1 perfect and 0 imperfect interpolant sequences [2021-11-23 03:30:16,085 INFO L186 FreeRefinementEngine]: Found 1 perfect and 0 imperfect interpolant sequences. [2021-11-23 03:30:16,085 INFO L199 FreeRefinementEngine]: Number of different interpolants: perfect sequences [6] imperfect sequences [] total 6 [2021-11-23 03:30:16,087 INFO L115 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [981322559] [2021-11-23 03:30:16,088 INFO L85 oduleStraightlineAll]: Using 1 perfect interpolants to construct interpolant automaton [2021-11-23 03:30:16,096 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 6 states [2021-11-23 03:30:16,097 INFO L103 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2021-11-23 03:30:16,137 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 6 interpolants. [2021-11-23 03:30:16,139 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=9, Invalid=21, Unknown=0, NotChecked=0, Total=30 [2021-11-23 03:30:16,141 INFO L87 Difference]: Start difference. First operand has 14 states, 12 states have (on average 1.5833333333333333) internal successors, (19), 13 states have internal predecessors, (19), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Second operand has 6 states, 6 states have (on average 1.3333333333333333) internal successors, (8), 6 states have internal predecessors, (8), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:16,342 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2021-11-23 03:30:16,343 INFO L93 Difference]: Finished difference Result 36 states and 41 transitions. [2021-11-23 03:30:16,344 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 8 states. [2021-11-23 03:30:16,346 INFO L78 Accepts]: Start accepts. Automaton has has 6 states, 6 states have (on average 1.3333333333333333) internal successors, (8), 6 states have internal predecessors, (8), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 8 [2021-11-23 03:30:16,347 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2021-11-23 03:30:16,357 INFO L225 Difference]: With dead ends: 36 [2021-11-23 03:30:16,357 INFO L226 Difference]: Without dead ends: 18 [2021-11-23 03:30:16,363 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 10 GetRequests, 2 SyntacticMatches, 0 SemanticMatches, 8 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 2 ImplicationChecksByTransitivity, 0.1s TimeCoverageRelationStatistics Valid=34, Invalid=56, Unknown=0, NotChecked=0, Total=90 [2021-11-23 03:30:16,370 INFO L933 BasicCegarLoop]: 8 mSDtfsCounter, 40 mSDsluCounter, 49 mSDsCounter, 0 mSdLazyCounter, 53 mSolverCounterSat, 2 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.1s Time, 0 mProtectedPredicate, 0 mProtectedAction, 40 SdHoareTripleChecker+Valid, 38 SdHoareTripleChecker+Invalid, 55 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 2 IncrementalHoareTripleChecker+Valid, 53 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.1s IncrementalHoareTripleChecker+Time [2021-11-23 03:30:16,373 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [40 Valid, 38 Invalid, 55 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [2 Valid, 53 Invalid, 0 Unknown, 0 Unchecked, 0.1s Time] [2021-11-23 03:30:16,395 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 18 states. [2021-11-23 03:30:16,414 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 18 to 13. [2021-11-23 03:30:16,415 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 13 states, 12 states have (on average 1.3333333333333333) internal successors, (16), 12 states have internal predecessors, (16), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:16,416 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 13 states to 13 states and 16 transitions. [2021-11-23 03:30:16,418 INFO L78 Accepts]: Start accepts. Automaton has 13 states and 16 transitions. Word has length 8 [2021-11-23 03:30:16,418 INFO L84 Accepts]: Finished accepts. word is rejected. [2021-11-23 03:30:16,419 INFO L470 AbstractCegarLoop]: Abstraction has 13 states and 16 transitions. [2021-11-23 03:30:16,419 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 6 states, 6 states have (on average 1.3333333333333333) internal successors, (8), 6 states have internal predecessors, (8), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:16,419 INFO L276 IsEmpty]: Start isEmpty. Operand 13 states and 16 transitions. [2021-11-23 03:30:16,420 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 10 [2021-11-23 03:30:16,420 INFO L506 BasicCegarLoop]: Found error trace [2021-11-23 03:30:16,421 INFO L514 BasicCegarLoop]: trace histogram [1, 1, 1, 1, 1, 1, 1, 1, 1] [2021-11-23 03:30:16,421 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable0 [2021-11-23 03:30:16,422 INFO L402 AbstractCegarLoop]: === Iteration 2 === Targeting ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION === [ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2021-11-23 03:30:16,427 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2021-11-23 03:30:16,427 INFO L85 PathProgramCache]: Analyzing trace with hash 390039330, now seen corresponding path program 1 times [2021-11-23 03:30:16,428 INFO L121 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2021-11-23 03:30:16,428 INFO L333 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1728115219] [2021-11-23 03:30:16,429 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:30:16,429 INFO L126 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2021-11-23 03:30:16,470 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:30:16,577 INFO L134 CoverageAnalysis]: Checked inductivity of 0 backedges. 0 proven. 0 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:30:16,578 INFO L139 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2021-11-23 03:30:16,578 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1728115219] [2021-11-23 03:30:16,578 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1728115219] provided 1 perfect and 0 imperfect interpolant sequences [2021-11-23 03:30:16,579 INFO L186 FreeRefinementEngine]: Found 1 perfect and 0 imperfect interpolant sequences. [2021-11-23 03:30:16,579 INFO L199 FreeRefinementEngine]: Number of different interpolants: perfect sequences [3] imperfect sequences [] total 3 [2021-11-23 03:30:16,579 INFO L115 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [805174837] [2021-11-23 03:30:16,579 INFO L85 oduleStraightlineAll]: Using 1 perfect interpolants to construct interpolant automaton [2021-11-23 03:30:16,581 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 3 states [2021-11-23 03:30:16,581 INFO L103 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2021-11-23 03:30:16,582 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 3 interpolants. [2021-11-23 03:30:16,582 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=3, Invalid=3, Unknown=0, NotChecked=0, Total=6 [2021-11-23 03:30:16,583 INFO L87 Difference]: Start difference. First operand 13 states and 16 transitions. Second operand has 3 states, 3 states have (on average 3.0) internal successors, (9), 3 states have internal predecessors, (9), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:16,630 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2021-11-23 03:30:16,630 INFO L93 Difference]: Finished difference Result 18 states and 21 transitions. [2021-11-23 03:30:16,630 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 3 states. [2021-11-23 03:30:16,631 INFO L78 Accepts]: Start accepts. Automaton has has 3 states, 3 states have (on average 3.0) internal successors, (9), 3 states have internal predecessors, (9), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 9 [2021-11-23 03:30:16,631 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2021-11-23 03:30:16,632 INFO L225 Difference]: With dead ends: 18 [2021-11-23 03:30:16,632 INFO L226 Difference]: Without dead ends: 14 [2021-11-23 03:30:16,632 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 3 GetRequests, 2 SyntacticMatches, 0 SemanticMatches, 1 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 0 ImplicationChecksByTransitivity, 0.0s TimeCoverageRelationStatistics Valid=3, Invalid=3, Unknown=0, NotChecked=0, Total=6 [2021-11-23 03:30:16,634 INFO L933 BasicCegarLoop]: 7 mSDtfsCounter, 0 mSDsluCounter, 9 mSDsCounter, 0 mSdLazyCounter, 15 mSolverCounterSat, 0 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.0s Time, 0 mProtectedPredicate, 0 mProtectedAction, 0 SdHoareTripleChecker+Valid, 12 SdHoareTripleChecker+Invalid, 15 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 0 IncrementalHoareTripleChecker+Valid, 15 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.0s IncrementalHoareTripleChecker+Time [2021-11-23 03:30:16,635 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [0 Valid, 12 Invalid, 15 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [0 Valid, 15 Invalid, 0 Unknown, 0 Unchecked, 0.0s Time] [2021-11-23 03:30:16,637 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 14 states. [2021-11-23 03:30:16,640 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 14 to 14. [2021-11-23 03:30:16,640 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 14 states, 13 states have (on average 1.3076923076923077) internal successors, (17), 13 states have internal predecessors, (17), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:16,641 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 14 states to 14 states and 17 transitions. [2021-11-23 03:30:16,641 INFO L78 Accepts]: Start accepts. Automaton has 14 states and 17 transitions. Word has length 9 [2021-11-23 03:30:16,642 INFO L84 Accepts]: Finished accepts. word is rejected. [2021-11-23 03:30:16,642 INFO L470 AbstractCegarLoop]: Abstraction has 14 states and 17 transitions. [2021-11-23 03:30:16,642 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 3 states, 3 states have (on average 3.0) internal successors, (9), 3 states have internal predecessors, (9), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:16,642 INFO L276 IsEmpty]: Start isEmpty. Operand 14 states and 17 transitions. [2021-11-23 03:30:16,643 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 10 [2021-11-23 03:30:16,643 INFO L506 BasicCegarLoop]: Found error trace [2021-11-23 03:30:16,643 INFO L514 BasicCegarLoop]: trace histogram [1, 1, 1, 1, 1, 1, 1, 1, 1] [2021-11-23 03:30:16,644 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable1 [2021-11-23 03:30:16,644 INFO L402 AbstractCegarLoop]: === Iteration 3 === Targeting ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION === [ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2021-11-23 03:30:16,645 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2021-11-23 03:30:16,645 INFO L85 PathProgramCache]: Analyzing trace with hash -1862814498, now seen corresponding path program 1 times [2021-11-23 03:30:16,650 INFO L121 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2021-11-23 03:30:16,650 INFO L333 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1919623767] [2021-11-23 03:30:16,651 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:30:16,651 INFO L126 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2021-11-23 03:30:16,683 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:30:16,724 INFO L134 CoverageAnalysis]: Checked inductivity of 0 backedges. 0 proven. 0 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:30:16,724 INFO L139 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2021-11-23 03:30:16,725 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1919623767] [2021-11-23 03:30:16,725 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1919623767] provided 1 perfect and 0 imperfect interpolant sequences [2021-11-23 03:30:16,727 INFO L186 FreeRefinementEngine]: Found 1 perfect and 0 imperfect interpolant sequences. [2021-11-23 03:30:16,727 INFO L199 FreeRefinementEngine]: Number of different interpolants: perfect sequences [3] imperfect sequences [] total 3 [2021-11-23 03:30:16,728 INFO L115 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1810653592] [2021-11-23 03:30:16,728 INFO L85 oduleStraightlineAll]: Using 1 perfect interpolants to construct interpolant automaton [2021-11-23 03:30:16,728 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 3 states [2021-11-23 03:30:16,729 INFO L103 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2021-11-23 03:30:16,731 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 3 interpolants. [2021-11-23 03:30:16,731 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=3, Invalid=3, Unknown=0, NotChecked=0, Total=6 [2021-11-23 03:30:16,732 INFO L87 Difference]: Start difference. First operand 14 states and 17 transitions. Second operand has 3 states, 3 states have (on average 3.0) internal successors, (9), 3 states have internal predecessors, (9), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:16,768 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2021-11-23 03:30:16,769 INFO L93 Difference]: Finished difference Result 23 states and 28 transitions. [2021-11-23 03:30:16,769 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 3 states. [2021-11-23 03:30:16,769 INFO L78 Accepts]: Start accepts. Automaton has has 3 states, 3 states have (on average 3.0) internal successors, (9), 3 states have internal predecessors, (9), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 9 [2021-11-23 03:30:16,770 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2021-11-23 03:30:16,772 INFO L225 Difference]: With dead ends: 23 [2021-11-23 03:30:16,772 INFO L226 Difference]: Without dead ends: 15 [2021-11-23 03:30:16,773 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 3 GetRequests, 2 SyntacticMatches, 0 SemanticMatches, 1 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 0 ImplicationChecksByTransitivity, 0.0s TimeCoverageRelationStatistics Valid=3, Invalid=3, Unknown=0, NotChecked=0, Total=6 [2021-11-23 03:30:16,781 INFO L933 BasicCegarLoop]: 7 mSDtfsCounter, 0 mSDsluCounter, 9 mSDsCounter, 0 mSdLazyCounter, 16 mSolverCounterSat, 0 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.0s Time, 0 mProtectedPredicate, 0 mProtectedAction, 0 SdHoareTripleChecker+Valid, 11 SdHoareTripleChecker+Invalid, 16 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 0 IncrementalHoareTripleChecker+Valid, 16 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.0s IncrementalHoareTripleChecker+Time [2021-11-23 03:30:16,783 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [0 Valid, 11 Invalid, 16 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [0 Valid, 16 Invalid, 0 Unknown, 0 Unchecked, 0.0s Time] [2021-11-23 03:30:16,785 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 15 states. [2021-11-23 03:30:16,791 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 15 to 15. [2021-11-23 03:30:16,792 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 15 states, 14 states have (on average 1.2857142857142858) internal successors, (18), 14 states have internal predecessors, (18), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:16,793 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 15 states to 15 states and 18 transitions. [2021-11-23 03:30:16,793 INFO L78 Accepts]: Start accepts. Automaton has 15 states and 18 transitions. Word has length 9 [2021-11-23 03:30:16,795 INFO L84 Accepts]: Finished accepts. word is rejected. [2021-11-23 03:30:16,795 INFO L470 AbstractCegarLoop]: Abstraction has 15 states and 18 transitions. [2021-11-23 03:30:16,795 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 3 states, 3 states have (on average 3.0) internal successors, (9), 3 states have internal predecessors, (9), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:16,796 INFO L276 IsEmpty]: Start isEmpty. Operand 15 states and 18 transitions. [2021-11-23 03:30:16,796 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 11 [2021-11-23 03:30:16,796 INFO L506 BasicCegarLoop]: Found error trace [2021-11-23 03:30:16,796 INFO L514 BasicCegarLoop]: trace histogram [1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2021-11-23 03:30:16,797 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable2 [2021-11-23 03:30:16,797 INFO L402 AbstractCegarLoop]: === Iteration 4 === Targeting ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION === [ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2021-11-23 03:30:16,798 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2021-11-23 03:30:16,798 INFO L85 PathProgramCache]: Analyzing trace with hash -803583839, now seen corresponding path program 1 times [2021-11-23 03:30:16,798 INFO L121 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2021-11-23 03:30:16,799 INFO L333 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [5645614] [2021-11-23 03:30:16,799 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:30:16,799 INFO L126 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2021-11-23 03:30:16,834 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:30:16,913 INFO L134 CoverageAnalysis]: Checked inductivity of 1 backedges. 0 proven. 1 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:30:16,913 INFO L139 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2021-11-23 03:30:16,914 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [5645614] [2021-11-23 03:30:16,914 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [5645614] provided 0 perfect and 1 imperfect interpolant sequences [2021-11-23 03:30:16,914 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [553628110] [2021-11-23 03:30:16,915 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:30:16,915 INFO L168 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:30:16,915 INFO L189 MonitoredProcess]: No working directory specified, using /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 [2021-11-23 03:30:16,920 INFO L229 MonitoredProcess]: Starting monitored process 2 with /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2021-11-23 03:30:16,925 INFO L327 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (2)] Waiting until timeout for monitored process [2021-11-23 03:30:16,998 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:30:17,000 INFO L263 TraceCheckSpWp]: Trace formula consists of 77 conjuncts, 6 conjunts are in the unsatisfiable core [2021-11-23 03:30:17,007 INFO L286 TraceCheckSpWp]: Computing forward predicates... [2021-11-23 03:30:17,626 INFO L134 CoverageAnalysis]: Checked inductivity of 1 backedges. 0 proven. 0 refuted. 0 times theorem prover too weak. 1 trivial. 0 not checked. [2021-11-23 03:30:17,626 INFO L324 TraceCheckSpWp]: Omiting computation of backward sequence because forward sequence was already perfect [2021-11-23 03:30:17,627 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleZ3 [553628110] provided 1 perfect and 0 imperfect interpolant sequences [2021-11-23 03:30:17,627 INFO L186 FreeRefinementEngine]: Found 1 perfect and 1 imperfect interpolant sequences. [2021-11-23 03:30:17,633 INFO L199 FreeRefinementEngine]: Number of different interpolants: perfect sequences [5] imperfect sequences [4] total 7 [2021-11-23 03:30:17,634 INFO L115 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [511883618] [2021-11-23 03:30:17,634 INFO L85 oduleStraightlineAll]: Using 1 perfect interpolants to construct interpolant automaton [2021-11-23 03:30:17,634 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 5 states [2021-11-23 03:30:17,635 INFO L103 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2021-11-23 03:30:17,635 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 5 interpolants. [2021-11-23 03:30:17,635 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=12, Invalid=30, Unknown=0, NotChecked=0, Total=42 [2021-11-23 03:30:17,636 INFO L87 Difference]: Start difference. First operand 15 states and 18 transitions. Second operand has 5 states, 5 states have (on average 2.0) internal successors, (10), 5 states have internal predecessors, (10), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:17,776 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2021-11-23 03:30:17,776 INFO L93 Difference]: Finished difference Result 25 states and 27 transitions. [2021-11-23 03:30:17,777 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 6 states. [2021-11-23 03:30:17,777 INFO L78 Accepts]: Start accepts. Automaton has has 5 states, 5 states have (on average 2.0) internal successors, (10), 5 states have internal predecessors, (10), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 10 [2021-11-23 03:30:17,778 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2021-11-23 03:30:17,778 INFO L225 Difference]: With dead ends: 25 [2021-11-23 03:30:17,778 INFO L226 Difference]: Without dead ends: 17 [2021-11-23 03:30:17,779 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 16 GetRequests, 8 SyntacticMatches, 0 SemanticMatches, 8 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 5 ImplicationChecksByTransitivity, 0.1s TimeCoverageRelationStatistics Valid=27, Invalid=63, Unknown=0, NotChecked=0, Total=90 [2021-11-23 03:30:17,780 INFO L933 BasicCegarLoop]: 5 mSDtfsCounter, 20 mSDsluCounter, 12 mSDsCounter, 0 mSdLazyCounter, 29 mSolverCounterSat, 1 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.0s Time, 0 mProtectedPredicate, 0 mProtectedAction, 20 SdHoareTripleChecker+Valid, 12 SdHoareTripleChecker+Invalid, 30 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 1 IncrementalHoareTripleChecker+Valid, 29 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.0s IncrementalHoareTripleChecker+Time [2021-11-23 03:30:17,781 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [20 Valid, 12 Invalid, 30 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [1 Valid, 29 Invalid, 0 Unknown, 0 Unchecked, 0.0s Time] [2021-11-23 03:30:17,782 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 17 states. [2021-11-23 03:30:17,786 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 17 to 13. [2021-11-23 03:30:17,786 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 13 states, 12 states have (on average 1.25) internal successors, (15), 12 states have internal predecessors, (15), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:17,787 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 13 states to 13 states and 15 transitions. [2021-11-23 03:30:17,787 INFO L78 Accepts]: Start accepts. Automaton has 13 states and 15 transitions. Word has length 10 [2021-11-23 03:30:17,788 INFO L84 Accepts]: Finished accepts. word is rejected. [2021-11-23 03:30:17,788 INFO L470 AbstractCegarLoop]: Abstraction has 13 states and 15 transitions. [2021-11-23 03:30:17,788 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 5 states, 5 states have (on average 2.0) internal successors, (10), 5 states have internal predecessors, (10), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:17,789 INFO L276 IsEmpty]: Start isEmpty. Operand 13 states and 15 transitions. [2021-11-23 03:30:17,789 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 11 [2021-11-23 03:30:17,789 INFO L506 BasicCegarLoop]: Found error trace [2021-11-23 03:30:17,790 INFO L514 BasicCegarLoop]: trace histogram [1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2021-11-23 03:30:17,837 INFO L540 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (2)] Forceful destruction successful, exit code 0 [2021-11-23 03:30:18,017 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable3,2 /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:30:18,018 INFO L402 AbstractCegarLoop]: === Iteration 5 === Targeting ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION === [ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2021-11-23 03:30:18,018 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2021-11-23 03:30:18,019 INFO L85 PathProgramCache]: Analyzing trace with hash -1928566110, now seen corresponding path program 1 times [2021-11-23 03:30:18,019 INFO L121 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2021-11-23 03:30:18,019 INFO L333 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [356180388] [2021-11-23 03:30:18,019 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:30:18,020 INFO L126 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2021-11-23 03:30:18,035 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:30:18,071 INFO L134 CoverageAnalysis]: Checked inductivity of 1 backedges. 0 proven. 1 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:30:18,071 INFO L139 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2021-11-23 03:30:18,071 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [356180388] [2021-11-23 03:30:18,072 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [356180388] provided 0 perfect and 1 imperfect interpolant sequences [2021-11-23 03:30:18,072 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [593862506] [2021-11-23 03:30:18,072 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:30:18,072 INFO L168 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:30:18,073 INFO L189 MonitoredProcess]: No working directory specified, using /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 [2021-11-23 03:30:18,074 INFO L229 MonitoredProcess]: Starting monitored process 3 with /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2021-11-23 03:30:18,093 INFO L327 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (3)] Waiting until timeout for monitored process [2021-11-23 03:30:18,135 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:30:18,148 INFO L263 TraceCheckSpWp]: Trace formula consists of 77 conjuncts, 4 conjunts are in the unsatisfiable core [2021-11-23 03:30:18,149 INFO L286 TraceCheckSpWp]: Computing forward predicates... [2021-11-23 03:30:18,200 INFO L134 CoverageAnalysis]: Checked inductivity of 1 backedges. 0 proven. 1 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:30:18,200 INFO L328 TraceCheckSpWp]: Computing backward predicates... [2021-11-23 03:30:18,242 INFO L134 CoverageAnalysis]: Checked inductivity of 1 backedges. 0 proven. 1 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:30:18,242 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleZ3 [593862506] provided 0 perfect and 2 imperfect interpolant sequences [2021-11-23 03:30:18,243 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [1380258515] [2021-11-23 03:30:18,294 INFO L159 IcfgInterpreter]: Started Sifa with 10 locations of interest [2021-11-23 03:30:18,294 INFO L166 IcfgInterpreter]: Building call graph [2021-11-23 03:30:18,300 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2021-11-23 03:30:18,306 INFO L176 IcfgInterpreter]: Starting interpretation [2021-11-23 03:30:18,307 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2021-11-23 03:30:18,695 INFO L180 IcfgInterpreter]: Interpretation finished [2021-11-23 03:30:19,608 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '366#(and (< |ULTIMATE.start_student_version_~w#1| 4) (= |ULTIMATE.start_correct_version_~i~0#1| |ULTIMATE.start_correct_version_~w#1|) (<= 4 |ULTIMATE.start_correct_version_~w#1|) (= ~true~0 1) (<= |ULTIMATE.start_correct_version_~is_divisible~0#1| 1) (= |ULTIMATE.start_correct_version_#res#1| |ULTIMATE.start_main_~is_divisible1~0#1|) (<= 4 |ULTIMATE.start_correct_version_#in~w#1|) (= ~false~0 0) (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_#in~w#1|) (= |ULTIMATE.start_student_version_#in~w#1| (ite (<= (mod |ULTIMATE.start_main_~w~0#1| 4294967296) 2147483647) (mod |ULTIMATE.start_main_~w~0#1| 4294967296) (+ (mod |ULTIMATE.start_main_~w~0#1| 4294967296) (- 4294967296)))) (= |ULTIMATE.start_correct_version_#res#1| |ULTIMATE.start_correct_version_~is_divisible~0#1|) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (= |#NULL.offset| 0) (= (ite (= |ULTIMATE.start_main_~is_divisible1~0#1| |ULTIMATE.start_main_~is_divisible2~0#1|) 1 0) |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (= |ULTIMATE.start_student_version_~is_divisible~1#1| ~false~0) (= |ULTIMATE.start_student_version_~is_divisible~1#1| |ULTIMATE.start_student_version_#res#1|) (<= 0 |#StackHeapBarrier|) (<= 1 |ULTIMATE.start_correct_version_~is_divisible~0#1|) (= |ULTIMATE.start_main_~is_divisible2~0#1| |ULTIMATE.start_student_version_#res#1|) (= |#NULL.base| 0))' at error location [2021-11-23 03:30:19,609 WARN L312 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2021-11-23 03:30:19,609 INFO L186 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2021-11-23 03:30:19,609 INFO L199 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [4, 4, 4] total 8 [2021-11-23 03:30:19,609 INFO L115 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1108739906] [2021-11-23 03:30:19,609 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2021-11-23 03:30:19,610 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 8 states [2021-11-23 03:30:19,610 INFO L103 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2021-11-23 03:30:19,611 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 8 interpolants. [2021-11-23 03:30:19,611 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=45, Invalid=195, Unknown=0, NotChecked=0, Total=240 [2021-11-23 03:30:19,612 INFO L87 Difference]: Start difference. First operand 13 states and 15 transitions. Second operand has 8 states, 8 states have (on average 2.0) internal successors, (16), 8 states have internal predecessors, (16), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:19,657 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2021-11-23 03:30:19,658 INFO L93 Difference]: Finished difference Result 22 states and 26 transitions. [2021-11-23 03:30:19,658 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 4 states. [2021-11-23 03:30:19,659 INFO L78 Accepts]: Start accepts. Automaton has has 8 states, 8 states have (on average 2.0) internal successors, (16), 8 states have internal predecessors, (16), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 10 [2021-11-23 03:30:19,659 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2021-11-23 03:30:19,660 INFO L225 Difference]: With dead ends: 22 [2021-11-23 03:30:19,660 INFO L226 Difference]: Without dead ends: 14 [2021-11-23 03:30:19,660 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 32 GetRequests, 18 SyntacticMatches, 0 SemanticMatches, 14 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 75 ImplicationChecksByTransitivity, 0.9s TimeCoverageRelationStatistics Valid=45, Invalid=195, Unknown=0, NotChecked=0, Total=240 [2021-11-23 03:30:19,662 INFO L933 BasicCegarLoop]: 6 mSDtfsCounter, 0 mSDsluCounter, 45 mSDsCounter, 0 mSdLazyCounter, 47 mSolverCounterSat, 1 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.0s Time, 0 mProtectedPredicate, 0 mProtectedAction, 0 SdHoareTripleChecker+Valid, 26 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 [2021-11-23 03:30:19,662 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [0 Valid, 26 Invalid, 48 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [1 Valid, 47 Invalid, 0 Unknown, 0 Unchecked, 0.0s Time] [2021-11-23 03:30:19,663 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 14 states. [2021-11-23 03:30:19,666 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 14 to 14. [2021-11-23 03:30:19,667 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 14 states, 13 states have (on average 1.2307692307692308) internal successors, (16), 13 states have internal predecessors, (16), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:19,667 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 14 states to 14 states and 16 transitions. [2021-11-23 03:30:19,668 INFO L78 Accepts]: Start accepts. Automaton has 14 states and 16 transitions. Word has length 10 [2021-11-23 03:30:19,668 INFO L84 Accepts]: Finished accepts. word is rejected. [2021-11-23 03:30:19,668 INFO L470 AbstractCegarLoop]: Abstraction has 14 states and 16 transitions. [2021-11-23 03:30:19,668 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 8 states, 8 states have (on average 2.0) internal successors, (16), 8 states have internal predecessors, (16), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:19,669 INFO L276 IsEmpty]: Start isEmpty. Operand 14 states and 16 transitions. [2021-11-23 03:30:19,669 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 12 [2021-11-23 03:30:19,669 INFO L506 BasicCegarLoop]: Found error trace [2021-11-23 03:30:19,670 INFO L514 BasicCegarLoop]: trace histogram [2, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2021-11-23 03:30:19,714 INFO L540 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (3)] Forceful destruction successful, exit code 0 [2021-11-23 03:30:19,885 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable4,3 /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:30:19,886 INFO L402 AbstractCegarLoop]: === Iteration 6 === Targeting ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION === [ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2021-11-23 03:30:19,886 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2021-11-23 03:30:19,886 INFO L85 PathProgramCache]: Analyzing trace with hash 328101214, now seen corresponding path program 2 times [2021-11-23 03:30:19,886 INFO L121 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2021-11-23 03:30:19,887 INFO L333 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1681489304] [2021-11-23 03:30:19,887 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:30:19,887 INFO L126 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2021-11-23 03:30:19,923 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:30:20,070 INFO L134 CoverageAnalysis]: Checked inductivity of 3 backedges. 0 proven. 0 refuted. 0 times theorem prover too weak. 3 trivial. 0 not checked. [2021-11-23 03:30:20,071 INFO L139 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2021-11-23 03:30:20,071 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1681489304] [2021-11-23 03:30:20,071 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1681489304] provided 1 perfect and 0 imperfect interpolant sequences [2021-11-23 03:30:20,071 INFO L186 FreeRefinementEngine]: Found 1 perfect and 0 imperfect interpolant sequences. [2021-11-23 03:30:20,072 INFO L199 FreeRefinementEngine]: Number of different interpolants: perfect sequences [6] imperfect sequences [] total 6 [2021-11-23 03:30:20,072 INFO L115 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [511976501] [2021-11-23 03:30:20,072 INFO L85 oduleStraightlineAll]: Using 1 perfect interpolants to construct interpolant automaton [2021-11-23 03:30:20,073 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 6 states [2021-11-23 03:30:20,073 INFO L103 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2021-11-23 03:30:20,074 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 6 interpolants. [2021-11-23 03:30:20,074 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=11, Invalid=19, Unknown=0, NotChecked=0, Total=30 [2021-11-23 03:30:20,074 INFO L87 Difference]: Start difference. First operand 14 states and 16 transitions. Second operand has 6 states, 6 states have (on average 1.6666666666666667) internal successors, (10), 6 states have internal predecessors, (10), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:20,119 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2021-11-23 03:30:20,119 INFO L93 Difference]: Finished difference Result 18 states and 19 transitions. [2021-11-23 03:30:20,120 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 5 states. [2021-11-23 03:30:20,121 INFO L78 Accepts]: Start accepts. Automaton has has 6 states, 6 states have (on average 1.6666666666666667) internal successors, (10), 6 states have internal predecessors, (10), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 11 [2021-11-23 03:30:20,121 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2021-11-23 03:30:20,122 INFO L225 Difference]: With dead ends: 18 [2021-11-23 03:30:20,123 INFO L226 Difference]: Without dead ends: 14 [2021-11-23 03:30:20,125 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 7 GetRequests, 2 SyntacticMatches, 0 SemanticMatches, 5 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 3 ImplicationChecksByTransitivity, 0.1s TimeCoverageRelationStatistics Valid=17, Invalid=25, Unknown=0, NotChecked=0, Total=42 [2021-11-23 03:30:20,128 INFO L933 BasicCegarLoop]: 3 mSDtfsCounter, 24 mSDsluCounter, 2 mSDsCounter, 0 mSdLazyCounter, 16 mSolverCounterSat, 1 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.0s Time, 0 mProtectedPredicate, 0 mProtectedAction, 24 SdHoareTripleChecker+Valid, 4 SdHoareTripleChecker+Invalid, 17 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 1 IncrementalHoareTripleChecker+Valid, 16 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.0s IncrementalHoareTripleChecker+Time [2021-11-23 03:30:20,129 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [24 Valid, 4 Invalid, 17 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [1 Valid, 16 Invalid, 0 Unknown, 0 Unchecked, 0.0s Time] [2021-11-23 03:30:20,130 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 14 states. [2021-11-23 03:30:20,138 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 14 to 14. [2021-11-23 03:30:20,139 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 14 states, 13 states have (on average 1.1538461538461537) internal successors, (15), 13 states have internal predecessors, (15), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:20,141 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 14 states to 14 states and 15 transitions. [2021-11-23 03:30:20,142 INFO L78 Accepts]: Start accepts. Automaton has 14 states and 15 transitions. Word has length 11 [2021-11-23 03:30:20,142 INFO L84 Accepts]: Finished accepts. word is rejected. [2021-11-23 03:30:20,144 INFO L470 AbstractCegarLoop]: Abstraction has 14 states and 15 transitions. [2021-11-23 03:30:20,145 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 6 states, 6 states have (on average 1.6666666666666667) internal successors, (10), 6 states have internal predecessors, (10), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:20,145 INFO L276 IsEmpty]: Start isEmpty. Operand 14 states and 15 transitions. [2021-11-23 03:30:20,147 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 14 [2021-11-23 03:30:20,147 INFO L506 BasicCegarLoop]: Found error trace [2021-11-23 03:30:20,147 INFO L514 BasicCegarLoop]: trace histogram [2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2021-11-23 03:30:20,147 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable5 [2021-11-23 03:30:20,148 INFO L402 AbstractCegarLoop]: === Iteration 7 === Targeting ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION === [ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2021-11-23 03:30:20,148 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2021-11-23 03:30:20,148 INFO L85 PathProgramCache]: Analyzing trace with hash 1827995217, now seen corresponding path program 1 times [2021-11-23 03:30:20,149 INFO L121 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2021-11-23 03:30:20,149 INFO L333 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1877555454] [2021-11-23 03:30:20,149 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:30:20,149 INFO L126 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2021-11-23 03:30:20,182 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:30:20,211 INFO L134 CoverageAnalysis]: Checked inductivity of 4 backedges. 0 proven. 1 refuted. 0 times theorem prover too weak. 3 trivial. 0 not checked. [2021-11-23 03:30:20,212 INFO L139 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2021-11-23 03:30:20,212 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1877555454] [2021-11-23 03:30:20,212 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1877555454] provided 0 perfect and 1 imperfect interpolant sequences [2021-11-23 03:30:20,213 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [561596493] [2021-11-23 03:30:20,213 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:30:20,213 INFO L168 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:30:20,213 INFO L189 MonitoredProcess]: No working directory specified, using /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 [2021-11-23 03:30:20,214 INFO L229 MonitoredProcess]: Starting monitored process 4 with /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2021-11-23 03:30:20,236 INFO L327 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (4)] Waiting until timeout for monitored process [2021-11-23 03:30:20,263 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:30:20,265 INFO L263 TraceCheckSpWp]: Trace formula consists of 85 conjuncts, 4 conjunts are in the unsatisfiable core [2021-11-23 03:30:20,266 INFO L286 TraceCheckSpWp]: Computing forward predicates... [2021-11-23 03:30:20,321 INFO L134 CoverageAnalysis]: Checked inductivity of 4 backedges. 0 proven. 1 refuted. 0 times theorem prover too weak. 3 trivial. 0 not checked. [2021-11-23 03:30:20,322 INFO L328 TraceCheckSpWp]: Computing backward predicates... [2021-11-23 03:30:20,363 INFO L134 CoverageAnalysis]: Checked inductivity of 4 backedges. 0 proven. 1 refuted. 0 times theorem prover too weak. 3 trivial. 0 not checked. [2021-11-23 03:30:20,363 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleZ3 [561596493] provided 0 perfect and 2 imperfect interpolant sequences [2021-11-23 03:30:20,364 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [192990231] [2021-11-23 03:30:20,366 INFO L159 IcfgInterpreter]: Started Sifa with 11 locations of interest [2021-11-23 03:30:20,367 INFO L166 IcfgInterpreter]: Building call graph [2021-11-23 03:30:20,367 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2021-11-23 03:30:20,367 INFO L176 IcfgInterpreter]: Starting interpretation [2021-11-23 03:30:20,368 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2021-11-23 03:30:20,747 INFO L180 IcfgInterpreter]: Interpretation finished [2021-11-23 03:30:21,897 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '563#(and (<= 4 |ULTIMATE.start_correct_version_~i~0#1|) (<= |ULTIMATE.start_correct_version_#res#1| 1) (<= 4 |ULTIMATE.start_student_version_~w#1|) (<= |ULTIMATE.start_main_~is_divisible1~0#1| 1) (<= 4 |ULTIMATE.start_correct_version_~w#1|) (<= 4 |ULTIMATE.start_student_version_#in~w#1|) (<= 0 |ULTIMATE.start_correct_version_~is_divisible~0#1|) (<= |ULTIMATE.start_correct_version_~is_divisible~0#1| 1) (<= ~false~0 0) (<= |#NULL.offset| 0) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| 0) (<= 0 ~false~0) (<= 4 |ULTIMATE.start_correct_version_#in~w#1|) (<= 1 ~true~0) (<= 0 |ULTIMATE.start_correct_version_#res#1|) (or (and (not (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|)) (= |ULTIMATE.start_student_version_~is_divisible~1#1| ~false~0)) (and (<= 1 |ULTIMATE.start_student_version_~is_divisible~1#1|) (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (<= |ULTIMATE.start_student_version_~is_divisible~1#1| 1))) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (= (ite (= |ULTIMATE.start_main_~is_divisible1~0#1| |ULTIMATE.start_main_~is_divisible2~0#1|) 1 0) |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (<= 0 |ULTIMATE.start_main_~is_divisible1~0#1|) (<= ~true~0 1) (= |ULTIMATE.start_student_version_~is_divisible~1#1| |ULTIMATE.start_student_version_#res#1|) (<= 0 |#NULL.offset|) (<= 0 |#StackHeapBarrier|) (= |ULTIMATE.start_main_~is_divisible2~0#1| |ULTIMATE.start_student_version_#res#1|) (<= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (= |#NULL.base| 0))' at error location [2021-11-23 03:30:21,897 WARN L312 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2021-11-23 03:30:21,897 INFO L186 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2021-11-23 03:30:21,897 INFO L199 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [4, 4, 4] total 8 [2021-11-23 03:30:21,898 INFO L115 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1446419177] [2021-11-23 03:30:21,898 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2021-11-23 03:30:21,898 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 8 states [2021-11-23 03:30:21,899 INFO L103 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2021-11-23 03:30:21,899 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 8 interpolants. [2021-11-23 03:30:21,899 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=47, Invalid=225, Unknown=0, NotChecked=0, Total=272 [2021-11-23 03:30:21,900 INFO L87 Difference]: Start difference. First operand 14 states and 15 transitions. Second operand has 8 states, 8 states have (on average 2.25) internal successors, (18), 8 states have internal predecessors, (18), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:21,923 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2021-11-23 03:30:21,924 INFO L93 Difference]: Finished difference Result 19 states and 20 transitions. [2021-11-23 03:30:21,924 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 4 states. [2021-11-23 03:30:21,925 INFO L78 Accepts]: Start accepts. Automaton has has 8 states, 8 states have (on average 2.25) internal successors, (18), 8 states have internal predecessors, (18), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 13 [2021-11-23 03:30:21,925 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2021-11-23 03:30:21,926 INFO L225 Difference]: With dead ends: 19 [2021-11-23 03:30:21,926 INFO L226 Difference]: Without dead ends: 15 [2021-11-23 03:30:21,926 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 41 GetRequests, 26 SyntacticMatches, 0 SemanticMatches, 15 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 84 ImplicationChecksByTransitivity, 1.2s TimeCoverageRelationStatistics Valid=47, Invalid=225, Unknown=0, NotChecked=0, Total=272 [2021-11-23 03:30:21,927 INFO L933 BasicCegarLoop]: 5 mSDtfsCounter, 0 mSDsluCounter, 8 mSDsCounter, 0 mSdLazyCounter, 17 mSolverCounterSat, 3 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.0s Time, 0 mProtectedPredicate, 0 mProtectedAction, 0 SdHoareTripleChecker+Valid, 9 SdHoareTripleChecker+Invalid, 20 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 3 IncrementalHoareTripleChecker+Valid, 17 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.0s IncrementalHoareTripleChecker+Time [2021-11-23 03:30:21,928 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [0 Valid, 9 Invalid, 20 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [3 Valid, 17 Invalid, 0 Unknown, 0 Unchecked, 0.0s Time] [2021-11-23 03:30:21,929 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 15 states. [2021-11-23 03:30:21,932 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 15 to 15. [2021-11-23 03:30:21,933 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 15 states, 14 states have (on average 1.1428571428571428) internal successors, (16), 14 states have internal predecessors, (16), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:21,933 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 15 states to 15 states and 16 transitions. [2021-11-23 03:30:21,934 INFO L78 Accepts]: Start accepts. Automaton has 15 states and 16 transitions. Word has length 13 [2021-11-23 03:30:21,934 INFO L84 Accepts]: Finished accepts. word is rejected. [2021-11-23 03:30:21,934 INFO L470 AbstractCegarLoop]: Abstraction has 15 states and 16 transitions. [2021-11-23 03:30:21,935 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 8 states, 8 states have (on average 2.25) internal successors, (18), 8 states have internal predecessors, (18), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:21,935 INFO L276 IsEmpty]: Start isEmpty. Operand 15 states and 16 transitions. [2021-11-23 03:30:21,935 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 15 [2021-11-23 03:30:21,935 INFO L506 BasicCegarLoop]: Found error trace [2021-11-23 03:30:21,936 INFO L514 BasicCegarLoop]: trace histogram [2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2021-11-23 03:30:21,977 INFO L540 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (4)] Forceful destruction successful, exit code 0 [2021-11-23 03:30:22,151 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: 4 /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true,SelfDestructingSolverStorable6 [2021-11-23 03:30:22,151 INFO L402 AbstractCegarLoop]: === Iteration 8 === Targeting ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION === [ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2021-11-23 03:30:22,152 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2021-11-23 03:30:22,152 INFO L85 PathProgramCache]: Analyzing trace with hash 823375698, now seen corresponding path program 2 times [2021-11-23 03:30:22,152 INFO L121 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2021-11-23 03:30:22,152 INFO L333 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [198786501] [2021-11-23 03:30:22,152 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:30:22,153 INFO L126 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2021-11-23 03:30:22,165 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:30:22,319 INFO L134 CoverageAnalysis]: Checked inductivity of 6 backedges. 0 proven. 6 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:30:22,319 INFO L139 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2021-11-23 03:30:22,320 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [198786501] [2021-11-23 03:30:22,320 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [198786501] provided 0 perfect and 1 imperfect interpolant sequences [2021-11-23 03:30:22,320 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1224798981] [2021-11-23 03:30:22,320 INFO L93 rtionOrderModulation]: Changing assertion order to OUTSIDE_LOOP_FIRST2 [2021-11-23 03:30:22,321 INFO L168 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:30:22,321 INFO L189 MonitoredProcess]: No working directory specified, using /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 [2021-11-23 03:30:22,326 INFO L229 MonitoredProcess]: Starting monitored process 5 with /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2021-11-23 03:30:22,344 INFO L327 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (5)] Waiting until timeout for monitored process [2021-11-23 03:30:22,388 INFO L228 tOrderPrioritization]: Assert order OUTSIDE_LOOP_FIRST2 issued 2 check-sat command(s) [2021-11-23 03:30:22,388 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2021-11-23 03:30:22,389 INFO L263 TraceCheckSpWp]: Trace formula consists of 88 conjuncts, 27 conjunts are in the unsatisfiable core [2021-11-23 03:30:22,391 INFO L286 TraceCheckSpWp]: Computing forward predicates... [2021-11-23 03:30:22,656 INFO L134 CoverageAnalysis]: Checked inductivity of 6 backedges. 0 proven. 6 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:30:22,656 INFO L328 TraceCheckSpWp]: Computing backward predicates... [2021-11-23 03:30:23,030 INFO L134 CoverageAnalysis]: Checked inductivity of 6 backedges. 0 proven. 6 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:30:23,030 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1224798981] provided 0 perfect and 2 imperfect interpolant sequences [2021-11-23 03:30:23,030 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [737362611] [2021-11-23 03:30:23,033 INFO L159 IcfgInterpreter]: Started Sifa with 11 locations of interest [2021-11-23 03:30:23,033 INFO L166 IcfgInterpreter]: Building call graph [2021-11-23 03:30:23,033 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2021-11-23 03:30:23,033 INFO L176 IcfgInterpreter]: Starting interpretation [2021-11-23 03:30:23,034 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2021-11-23 03:30:23,279 INFO L180 IcfgInterpreter]: Interpretation finished [2021-11-23 03:30:24,318 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '725#(and (<= 4 |ULTIMATE.start_correct_version_~i~0#1|) (<= |ULTIMATE.start_correct_version_#res#1| 1) (<= 4 |ULTIMATE.start_student_version_~w#1|) (<= |ULTIMATE.start_main_~is_divisible1~0#1| 1) (<= 4 |ULTIMATE.start_correct_version_~w#1|) (<= 4 |ULTIMATE.start_student_version_#in~w#1|) (<= 0 |ULTIMATE.start_correct_version_~is_divisible~0#1|) (<= |ULTIMATE.start_correct_version_~is_divisible~0#1| 1) (<= ~false~0 0) (<= |#NULL.offset| 0) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| 0) (<= 0 ~false~0) (<= 4 |ULTIMATE.start_correct_version_#in~w#1|) (<= 1 ~true~0) (<= 0 |ULTIMATE.start_correct_version_#res#1|) (or (and (not (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|)) (= |ULTIMATE.start_student_version_~is_divisible~1#1| ~false~0)) (and (<= 1 |ULTIMATE.start_student_version_~is_divisible~1#1|) (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (<= |ULTIMATE.start_student_version_~is_divisible~1#1| 1))) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (= (ite (= |ULTIMATE.start_main_~is_divisible1~0#1| |ULTIMATE.start_main_~is_divisible2~0#1|) 1 0) |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (<= 0 |ULTIMATE.start_main_~is_divisible1~0#1|) (<= ~true~0 1) (= |ULTIMATE.start_student_version_~is_divisible~1#1| |ULTIMATE.start_student_version_#res#1|) (<= 0 |#NULL.offset|) (<= 0 |#StackHeapBarrier|) (= |ULTIMATE.start_main_~is_divisible2~0#1| |ULTIMATE.start_student_version_#res#1|) (<= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (= |#NULL.base| 0))' at error location [2021-11-23 03:30:24,318 WARN L312 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2021-11-23 03:30:24,319 INFO L186 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2021-11-23 03:30:24,319 INFO L199 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [11, 11, 11] total 24 [2021-11-23 03:30:24,319 INFO L115 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1254130082] [2021-11-23 03:30:24,319 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2021-11-23 03:30:24,320 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 24 states [2021-11-23 03:30:24,320 INFO L103 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2021-11-23 03:30:24,321 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 24 interpolants. [2021-11-23 03:30:24,321 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=138, Invalid=918, Unknown=0, NotChecked=0, Total=1056 [2021-11-23 03:30:24,322 INFO L87 Difference]: Start difference. First operand 15 states and 16 transitions. Second operand has 24 states, 24 states have (on average 1.3333333333333333) internal successors, (32), 24 states have internal predecessors, (32), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:24,546 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2021-11-23 03:30:24,547 INFO L93 Difference]: Finished difference Result 30 states and 32 transitions. [2021-11-23 03:30:24,548 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 13 states. [2021-11-23 03:30:24,548 INFO L78 Accepts]: Start accepts. Automaton has has 24 states, 24 states have (on average 1.3333333333333333) internal successors, (32), 24 states have internal predecessors, (32), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 14 [2021-11-23 03:30:24,548 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2021-11-23 03:30:24,549 INFO L225 Difference]: With dead ends: 30 [2021-11-23 03:30:24,549 INFO L226 Difference]: Without dead ends: 26 [2021-11-23 03:30:24,550 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 58 GetRequests, 21 SyntacticMatches, 1 SemanticMatches, 36 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 621 ImplicationChecksByTransitivity, 1.4s TimeCoverageRelationStatistics Valid=204, Invalid=1202, Unknown=0, NotChecked=0, Total=1406 [2021-11-23 03:30:24,551 INFO L933 BasicCegarLoop]: 5 mSDtfsCounter, 11 mSDsluCounter, 52 mSDsCounter, 0 mSdLazyCounter, 113 mSolverCounterSat, 23 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.1s Time, 0 mProtectedPredicate, 0 mProtectedAction, 11 SdHoareTripleChecker+Valid, 47 SdHoareTripleChecker+Invalid, 136 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 23 IncrementalHoareTripleChecker+Valid, 113 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.1s IncrementalHoareTripleChecker+Time [2021-11-23 03:30:24,551 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [11 Valid, 47 Invalid, 136 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [23 Valid, 113 Invalid, 0 Unknown, 0 Unchecked, 0.1s Time] [2021-11-23 03:30:24,551 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 26 states. [2021-11-23 03:30:24,555 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 26 to 19. [2021-11-23 03:30:24,556 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 19 states, 18 states have (on average 1.1666666666666667) internal successors, (21), 18 states have internal predecessors, (21), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:24,556 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 19 states to 19 states and 21 transitions. [2021-11-23 03:30:24,556 INFO L78 Accepts]: Start accepts. Automaton has 19 states and 21 transitions. Word has length 14 [2021-11-23 03:30:24,556 INFO L84 Accepts]: Finished accepts. word is rejected. [2021-11-23 03:30:24,557 INFO L470 AbstractCegarLoop]: Abstraction has 19 states and 21 transitions. [2021-11-23 03:30:24,557 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 24 states, 24 states have (on average 1.3333333333333333) internal successors, (32), 24 states have internal predecessors, (32), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:24,557 INFO L276 IsEmpty]: Start isEmpty. Operand 19 states and 21 transitions. [2021-11-23 03:30:24,558 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 16 [2021-11-23 03:30:24,558 INFO L506 BasicCegarLoop]: Found error trace [2021-11-23 03:30:24,558 INFO L514 BasicCegarLoop]: trace histogram [3, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2021-11-23 03:30:24,595 INFO L540 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (5)] Forceful destruction successful, exit code 0 [2021-11-23 03:30:24,769 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: 5 /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true,SelfDestructingSolverStorable7 [2021-11-23 03:30:24,770 INFO L402 AbstractCegarLoop]: === Iteration 9 === Targeting ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION === [ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2021-11-23 03:30:24,770 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2021-11-23 03:30:24,770 INFO L85 PathProgramCache]: Analyzing trace with hash -255058319, now seen corresponding path program 3 times [2021-11-23 03:30:24,770 INFO L121 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2021-11-23 03:30:24,770 INFO L333 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [124093203] [2021-11-23 03:30:24,770 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:30:24,770 INFO L126 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2021-11-23 03:30:24,781 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:30:24,976 INFO L134 CoverageAnalysis]: Checked inductivity of 9 backedges. 4 proven. 5 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:30:24,977 INFO L139 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2021-11-23 03:30:24,977 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [124093203] [2021-11-23 03:30:24,977 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [124093203] provided 0 perfect and 1 imperfect interpolant sequences [2021-11-23 03:30:24,977 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [115046132] [2021-11-23 03:30:24,977 INFO L93 rtionOrderModulation]: Changing assertion order to TERMS_WITH_SMALL_CONSTANTS_FIRST [2021-11-23 03:30:24,977 INFO L168 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:30:24,977 INFO L189 MonitoredProcess]: No working directory specified, using /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 [2021-11-23 03:30:24,978 INFO L229 MonitoredProcess]: Starting monitored process 6 with /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2021-11-23 03:30:24,979 INFO L327 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (6)] Waiting until timeout for monitored process [2021-11-23 03:30:25,011 INFO L228 tOrderPrioritization]: Assert order TERMS_WITH_SMALL_CONSTANTS_FIRST issued 0 check-sat command(s) [2021-11-23 03:30:25,011 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2021-11-23 03:30:25,012 INFO L263 TraceCheckSpWp]: Trace formula consists of 91 conjuncts, 12 conjunts are in the unsatisfiable core [2021-11-23 03:30:25,013 INFO L286 TraceCheckSpWp]: Computing forward predicates... [2021-11-23 03:30:25,338 INFO L134 CoverageAnalysis]: Checked inductivity of 9 backedges. 6 proven. 3 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:30:25,339 INFO L328 TraceCheckSpWp]: Computing backward predicates... [2021-11-23 03:30:25,616 INFO L134 CoverageAnalysis]: Checked inductivity of 9 backedges. 6 proven. 3 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:30:25,616 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleZ3 [115046132] provided 0 perfect and 2 imperfect interpolant sequences [2021-11-23 03:30:25,616 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [254217751] [2021-11-23 03:30:25,618 INFO L159 IcfgInterpreter]: Started Sifa with 11 locations of interest [2021-11-23 03:30:25,619 INFO L166 IcfgInterpreter]: Building call graph [2021-11-23 03:30:25,619 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2021-11-23 03:30:25,619 INFO L176 IcfgInterpreter]: Starting interpretation [2021-11-23 03:30:25,619 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2021-11-23 03:30:25,822 INFO L180 IcfgInterpreter]: Interpretation finished [2021-11-23 03:30:26,744 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '927#(and (<= 4 |ULTIMATE.start_correct_version_~i~0#1|) (<= |ULTIMATE.start_correct_version_#res#1| 1) (<= 4 |ULTIMATE.start_student_version_~w#1|) (<= |ULTIMATE.start_main_~is_divisible1~0#1| 1) (<= 4 |ULTIMATE.start_correct_version_~w#1|) (<= 4 |ULTIMATE.start_student_version_#in~w#1|) (<= 0 |ULTIMATE.start_correct_version_~is_divisible~0#1|) (= ~true~0 1) (<= |ULTIMATE.start_correct_version_~is_divisible~0#1| 1) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| 0) (<= 4 |ULTIMATE.start_correct_version_#in~w#1|) (= ~false~0 0) (<= 0 |ULTIMATE.start_correct_version_#res#1|) (or (and (not (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|)) (= |ULTIMATE.start_student_version_~is_divisible~1#1| ~false~0)) (and (<= 1 |ULTIMATE.start_student_version_~is_divisible~1#1|) (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (<= |ULTIMATE.start_student_version_~is_divisible~1#1| 1))) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (= |#NULL.offset| 0) (= (ite (= |ULTIMATE.start_main_~is_divisible1~0#1| |ULTIMATE.start_main_~is_divisible2~0#1|) 1 0) |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (<= 0 |ULTIMATE.start_main_~is_divisible1~0#1|) (= |ULTIMATE.start_student_version_~is_divisible~1#1| |ULTIMATE.start_student_version_#res#1|) (<= 0 |#StackHeapBarrier|) (= |ULTIMATE.start_main_~is_divisible2~0#1| |ULTIMATE.start_student_version_#res#1|) (<= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (= |#NULL.base| 0))' at error location [2021-11-23 03:30:26,745 WARN L312 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2021-11-23 03:30:26,745 INFO L186 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2021-11-23 03:30:26,745 INFO L199 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [11, 11, 11] total 23 [2021-11-23 03:30:26,745 INFO L115 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [817854667] [2021-11-23 03:30:26,745 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2021-11-23 03:30:26,746 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 23 states [2021-11-23 03:30:26,746 INFO L103 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2021-11-23 03:30:26,746 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 23 interpolants. [2021-11-23 03:30:26,747 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=142, Invalid=850, Unknown=0, NotChecked=0, Total=992 [2021-11-23 03:30:26,748 INFO L87 Difference]: Start difference. First operand 19 states and 21 transitions. Second operand has 23 states, 23 states have (on average 1.3478260869565217) internal successors, (31), 23 states have internal predecessors, (31), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:27,063 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2021-11-23 03:30:27,063 INFO L93 Difference]: Finished difference Result 26 states and 28 transitions. [2021-11-23 03:30:27,063 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 12 states. [2021-11-23 03:30:27,064 INFO L78 Accepts]: Start accepts. Automaton has has 23 states, 23 states have (on average 1.3478260869565217) internal successors, (31), 23 states have internal predecessors, (31), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 15 [2021-11-23 03:30:27,064 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2021-11-23 03:30:27,064 INFO L225 Difference]: With dead ends: 26 [2021-11-23 03:30:27,064 INFO L226 Difference]: Without dead ends: 16 [2021-11-23 03:30:27,065 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 60 GetRequests, 21 SyntacticMatches, 3 SemanticMatches, 36 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 487 ImplicationChecksByTransitivity, 1.5s TimeCoverageRelationStatistics Valid=231, Invalid=1175, Unknown=0, NotChecked=0, Total=1406 [2021-11-23 03:30:27,066 INFO L933 BasicCegarLoop]: 3 mSDtfsCounter, 33 mSDsluCounter, 16 mSDsCounter, 0 mSdLazyCounter, 63 mSolverCounterSat, 23 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.1s Time, 0 mProtectedPredicate, 0 mProtectedAction, 33 SdHoareTripleChecker+Valid, 12 SdHoareTripleChecker+Invalid, 86 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 23 IncrementalHoareTripleChecker+Valid, 63 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.1s IncrementalHoareTripleChecker+Time [2021-11-23 03:30:27,066 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [33 Valid, 12 Invalid, 86 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [23 Valid, 63 Invalid, 0 Unknown, 0 Unchecked, 0.1s Time] [2021-11-23 03:30:27,067 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 16 states. [2021-11-23 03:30:27,070 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 16 to 16. [2021-11-23 03:30:27,070 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 16 states, 15 states have (on average 1.1333333333333333) internal successors, (17), 15 states have internal predecessors, (17), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:27,071 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 16 states to 16 states and 17 transitions. [2021-11-23 03:30:27,071 INFO L78 Accepts]: Start accepts. Automaton has 16 states and 17 transitions. Word has length 15 [2021-11-23 03:30:27,071 INFO L84 Accepts]: Finished accepts. word is rejected. [2021-11-23 03:30:27,071 INFO L470 AbstractCegarLoop]: Abstraction has 16 states and 17 transitions. [2021-11-23 03:30:27,071 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 23 states, 23 states have (on average 1.3478260869565217) internal successors, (31), 23 states have internal predecessors, (31), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:27,071 INFO L276 IsEmpty]: Start isEmpty. Operand 16 states and 17 transitions. [2021-11-23 03:30:27,072 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 16 [2021-11-23 03:30:27,072 INFO L506 BasicCegarLoop]: Found error trace [2021-11-23 03:30:27,072 INFO L514 BasicCegarLoop]: trace histogram [3, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2021-11-23 03:30:27,111 INFO L540 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (6)] Forceful destruction successful, exit code 0 [2021-11-23 03:30:27,272 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable8,6 /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:30:27,273 INFO L402 AbstractCegarLoop]: === Iteration 10 === Targeting ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION === [ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2021-11-23 03:30:27,273 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2021-11-23 03:30:27,273 INFO L85 PathProgramCache]: Analyzing trace with hash -853672946, now seen corresponding path program 4 times [2021-11-23 03:30:27,274 INFO L121 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2021-11-23 03:30:27,274 INFO L333 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1553097093] [2021-11-23 03:30:27,274 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:30:27,274 INFO L126 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2021-11-23 03:30:27,284 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:30:27,502 INFO L134 CoverageAnalysis]: Checked inductivity of 9 backedges. 1 proven. 8 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:30:27,502 INFO L139 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2021-11-23 03:30:27,502 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1553097093] [2021-11-23 03:30:27,502 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1553097093] provided 0 perfect and 1 imperfect interpolant sequences [2021-11-23 03:30:27,502 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1675164827] [2021-11-23 03:30:27,503 INFO L93 rtionOrderModulation]: Changing assertion order to NOT_INCREMENTALLY [2021-11-23 03:30:27,503 INFO L168 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:30:27,503 INFO L189 MonitoredProcess]: No working directory specified, using /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 [2021-11-23 03:30:27,509 INFO L229 MonitoredProcess]: Starting monitored process 7 with /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2021-11-23 03:30:27,515 INFO L327 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (7)] Waiting until timeout for monitored process [2021-11-23 03:30:27,550 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:30:27,551 INFO L263 TraceCheckSpWp]: Trace formula consists of 91 conjuncts, 12 conjunts are in the unsatisfiable core [2021-11-23 03:30:27,553 INFO L286 TraceCheckSpWp]: Computing forward predicates... [2021-11-23 03:30:27,922 INFO L134 CoverageAnalysis]: Checked inductivity of 9 backedges. 3 proven. 6 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:30:27,922 INFO L328 TraceCheckSpWp]: Computing backward predicates... [2021-11-23 03:30:28,172 INFO L134 CoverageAnalysis]: Checked inductivity of 9 backedges. 6 proven. 3 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:30:28,172 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1675164827] provided 0 perfect and 2 imperfect interpolant sequences [2021-11-23 03:30:28,173 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [583807087] [2021-11-23 03:30:28,175 INFO L159 IcfgInterpreter]: Started Sifa with 11 locations of interest [2021-11-23 03:30:28,175 INFO L166 IcfgInterpreter]: Building call graph [2021-11-23 03:30:28,175 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2021-11-23 03:30:28,176 INFO L176 IcfgInterpreter]: Starting interpretation [2021-11-23 03:30:28,176 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2021-11-23 03:30:28,377 INFO L180 IcfgInterpreter]: Interpretation finished [2021-11-23 03:30:29,145 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '1122#(and (<= 4 |ULTIMATE.start_correct_version_~i~0#1|) (<= |ULTIMATE.start_correct_version_#res#1| 1) (<= 4 |ULTIMATE.start_student_version_~w#1|) (<= |ULTIMATE.start_main_~is_divisible1~0#1| 1) (<= 4 |ULTIMATE.start_correct_version_~w#1|) (<= 4 |ULTIMATE.start_student_version_#in~w#1|) (<= 0 |ULTIMATE.start_correct_version_~is_divisible~0#1|) (= ~true~0 1) (<= |ULTIMATE.start_correct_version_~is_divisible~0#1| 1) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| 0) (<= 4 |ULTIMATE.start_correct_version_#in~w#1|) (= ~false~0 0) (<= 0 |ULTIMATE.start_correct_version_#res#1|) (or (and (not (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|)) (= |ULTIMATE.start_student_version_~is_divisible~1#1| ~false~0)) (and (<= 1 |ULTIMATE.start_student_version_~is_divisible~1#1|) (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (<= |ULTIMATE.start_student_version_~is_divisible~1#1| 1))) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (= |#NULL.offset| 0) (= (ite (= |ULTIMATE.start_main_~is_divisible1~0#1| |ULTIMATE.start_main_~is_divisible2~0#1|) 1 0) |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (<= 0 |ULTIMATE.start_main_~is_divisible1~0#1|) (= |ULTIMATE.start_student_version_~is_divisible~1#1| |ULTIMATE.start_student_version_#res#1|) (<= 0 |#StackHeapBarrier|) (= |ULTIMATE.start_main_~is_divisible2~0#1| |ULTIMATE.start_student_version_#res#1|) (<= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (= |#NULL.base| 0))' at error location [2021-11-23 03:30:29,145 WARN L312 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2021-11-23 03:30:29,145 INFO L186 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2021-11-23 03:30:29,145 INFO L199 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [12, 11, 11] total 24 [2021-11-23 03:30:29,146 INFO L115 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1341658525] [2021-11-23 03:30:29,146 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2021-11-23 03:30:29,146 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 24 states [2021-11-23 03:30:29,146 INFO L103 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2021-11-23 03:30:29,147 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 24 interpolants. [2021-11-23 03:30:29,148 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=150, Invalid=906, Unknown=0, NotChecked=0, Total=1056 [2021-11-23 03:30:29,148 INFO L87 Difference]: Start difference. First operand 16 states and 17 transitions. Second operand has 24 states, 24 states have (on average 1.3333333333333333) internal successors, (32), 24 states have internal predecessors, (32), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:29,421 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2021-11-23 03:30:29,421 INFO L93 Difference]: Finished difference Result 21 states and 22 transitions. [2021-11-23 03:30:29,430 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 11 states. [2021-11-23 03:30:29,430 INFO L78 Accepts]: Start accepts. Automaton has has 24 states, 24 states have (on average 1.3333333333333333) internal successors, (32), 24 states have internal predecessors, (32), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 15 [2021-11-23 03:30:29,430 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2021-11-23 03:30:29,431 INFO L225 Difference]: With dead ends: 21 [2021-11-23 03:30:29,431 INFO L226 Difference]: Without dead ends: 17 [2021-11-23 03:30:29,432 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 60 GetRequests, 20 SyntacticMatches, 4 SemanticMatches, 36 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 543 ImplicationChecksByTransitivity, 1.3s TimeCoverageRelationStatistics Valid=252, Invalid=1154, Unknown=0, NotChecked=0, Total=1406 [2021-11-23 03:30:29,433 INFO L933 BasicCegarLoop]: 3 mSDtfsCounter, 45 mSDsluCounter, 15 mSDsCounter, 0 mSdLazyCounter, 73 mSolverCounterSat, 25 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.1s Time, 0 mProtectedPredicate, 0 mProtectedAction, 45 SdHoareTripleChecker+Valid, 12 SdHoareTripleChecker+Invalid, 98 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 25 IncrementalHoareTripleChecker+Valid, 73 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.1s IncrementalHoareTripleChecker+Time [2021-11-23 03:30:29,433 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [45 Valid, 12 Invalid, 98 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [25 Valid, 73 Invalid, 0 Unknown, 0 Unchecked, 0.1s Time] [2021-11-23 03:30:29,434 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 17 states. [2021-11-23 03:30:29,436 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 17 to 17. [2021-11-23 03:30:29,437 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 17 states, 16 states have (on average 1.125) internal successors, (18), 16 states have internal predecessors, (18), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:29,437 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 17 states to 17 states and 18 transitions. [2021-11-23 03:30:29,437 INFO L78 Accepts]: Start accepts. Automaton has 17 states and 18 transitions. Word has length 15 [2021-11-23 03:30:29,438 INFO L84 Accepts]: Finished accepts. word is rejected. [2021-11-23 03:30:29,438 INFO L470 AbstractCegarLoop]: Abstraction has 17 states and 18 transitions. [2021-11-23 03:30:29,438 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 24 states, 24 states have (on average 1.3333333333333333) internal successors, (32), 24 states have internal predecessors, (32), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:29,438 INFO L276 IsEmpty]: Start isEmpty. Operand 17 states and 18 transitions. [2021-11-23 03:30:29,439 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 17 [2021-11-23 03:30:29,439 INFO L506 BasicCegarLoop]: Found error trace [2021-11-23 03:30:29,439 INFO L514 BasicCegarLoop]: trace histogram [3, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2021-11-23 03:30:29,460 INFO L540 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (7)] Forceful destruction successful, exit code 0 [2021-11-23 03:30:29,653 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: 7 /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true,SelfDestructingSolverStorable9 [2021-11-23 03:30:29,654 INFO L402 AbstractCegarLoop]: === Iteration 11 === Targeting ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION === [ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2021-11-23 03:30:29,654 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2021-11-23 03:30:29,654 INFO L85 PathProgramCache]: Analyzing trace with hash -703958731, now seen corresponding path program 5 times [2021-11-23 03:30:29,654 INFO L121 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2021-11-23 03:30:29,654 INFO L333 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1281924187] [2021-11-23 03:30:29,654 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:30:29,655 INFO L126 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2021-11-23 03:30:29,680 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:30:30,078 INFO L134 CoverageAnalysis]: Checked inductivity of 12 backedges. 0 proven. 12 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:30:30,078 INFO L139 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2021-11-23 03:30:30,078 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1281924187] [2021-11-23 03:30:30,079 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1281924187] provided 0 perfect and 1 imperfect interpolant sequences [2021-11-23 03:30:30,079 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1996270004] [2021-11-23 03:30:30,079 INFO L93 rtionOrderModulation]: Changing assertion order to OUTSIDE_LOOP_FIRST2 [2021-11-23 03:30:30,079 INFO L168 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:30:30,079 INFO L189 MonitoredProcess]: No working directory specified, using /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 [2021-11-23 03:30:30,085 INFO L229 MonitoredProcess]: Starting monitored process 8 with /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2021-11-23 03:30:30,105 INFO L327 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (8)] Waiting until timeout for monitored process [2021-11-23 03:30:30,136 INFO L228 tOrderPrioritization]: Assert order OUTSIDE_LOOP_FIRST2 issued 3 check-sat command(s) [2021-11-23 03:30:30,137 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2021-11-23 03:30:30,139 WARN L261 TraceCheckSpWp]: Trace formula consists of 94 conjuncts, 47 conjunts are in the unsatisfiable core [2021-11-23 03:30:30,140 INFO L286 TraceCheckSpWp]: Computing forward predicates... [2021-11-23 03:30:31,780 INFO L134 CoverageAnalysis]: Checked inductivity of 12 backedges. 0 proven. 12 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:30:31,780 INFO L328 TraceCheckSpWp]: Computing backward predicates... [2021-11-23 03:30:33,218 INFO L134 CoverageAnalysis]: Checked inductivity of 12 backedges. 0 proven. 12 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:30:33,219 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1996270004] provided 0 perfect and 2 imperfect interpolant sequences [2021-11-23 03:30:33,219 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [1812729234] [2021-11-23 03:30:33,224 INFO L159 IcfgInterpreter]: Started Sifa with 11 locations of interest [2021-11-23 03:30:33,224 INFO L166 IcfgInterpreter]: Building call graph [2021-11-23 03:30:33,225 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2021-11-23 03:30:33,225 INFO L176 IcfgInterpreter]: Starting interpretation [2021-11-23 03:30:33,226 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2021-11-23 03:30:33,491 INFO L180 IcfgInterpreter]: Interpretation finished [2021-11-23 03:30:35,022 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '1330#(and (<= 4 |ULTIMATE.start_correct_version_~i~0#1|) (<= |ULTIMATE.start_correct_version_#res#1| 1) (<= 4 |ULTIMATE.start_student_version_~w#1|) (<= |ULTIMATE.start_main_~is_divisible1~0#1| 1) (<= 4 |ULTIMATE.start_correct_version_~w#1|) (<= 4 |ULTIMATE.start_student_version_#in~w#1|) (<= 0 |ULTIMATE.start_correct_version_~is_divisible~0#1|) (<= |ULTIMATE.start_correct_version_~is_divisible~0#1| 1) (<= ~false~0 0) (<= |#NULL.offset| 0) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| 0) (<= 0 ~false~0) (<= 4 |ULTIMATE.start_correct_version_#in~w#1|) (<= 1 ~true~0) (<= 0 |ULTIMATE.start_correct_version_#res#1|) (or (and (not (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|)) (= |ULTIMATE.start_student_version_~is_divisible~1#1| ~false~0)) (and (<= 1 |ULTIMATE.start_student_version_~is_divisible~1#1|) (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (<= |ULTIMATE.start_student_version_~is_divisible~1#1| 1))) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (= (ite (= |ULTIMATE.start_main_~is_divisible1~0#1| |ULTIMATE.start_main_~is_divisible2~0#1|) 1 0) |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (<= 0 |ULTIMATE.start_main_~is_divisible1~0#1|) (<= ~true~0 1) (= |ULTIMATE.start_student_version_~is_divisible~1#1| |ULTIMATE.start_student_version_#res#1|) (<= 0 |#NULL.offset|) (<= 0 |#StackHeapBarrier|) (= |ULTIMATE.start_main_~is_divisible2~0#1| |ULTIMATE.start_student_version_#res#1|) (<= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (= |#NULL.base| 0))' at error location [2021-11-23 03:30:35,022 WARN L312 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2021-11-23 03:30:35,022 INFO L186 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2021-11-23 03:30:35,023 INFO L199 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [15, 15, 15] total 40 [2021-11-23 03:30:35,023 INFO L115 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1338551021] [2021-11-23 03:30:35,023 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2021-11-23 03:30:35,024 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 40 states [2021-11-23 03:30:35,024 INFO L103 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2021-11-23 03:30:35,025 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 40 interpolants. [2021-11-23 03:30:35,026 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=184, Invalid=2168, Unknown=0, NotChecked=0, Total=2352 [2021-11-23 03:30:35,026 INFO L87 Difference]: Start difference. First operand 17 states and 18 transitions. Second operand has 40 states, 40 states have (on average 1.1) internal successors, (44), 40 states have internal predecessors, (44), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:41,674 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2021-11-23 03:30:41,674 INFO L93 Difference]: Finished difference Result 61 states and 70 transitions. [2021-11-23 03:30:41,675 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 39 states. [2021-11-23 03:30:41,675 INFO L78 Accepts]: Start accepts. Automaton has has 40 states, 40 states have (on average 1.1) internal successors, (44), 40 states have internal predecessors, (44), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 16 [2021-11-23 03:30:41,675 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2021-11-23 03:30:41,675 INFO L225 Difference]: With dead ends: 61 [2021-11-23 03:30:41,676 INFO L226 Difference]: Without dead ends: 44 [2021-11-23 03:30:41,678 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 94 GetRequests, 13 SyntacticMatches, 1 SemanticMatches, 80 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 1747 ImplicationChecksByTransitivity, 9.5s TimeCoverageRelationStatistics Valid=678, Invalid=5964, Unknown=0, NotChecked=0, Total=6642 [2021-11-23 03:30:41,679 INFO L933 BasicCegarLoop]: 2 mSDtfsCounter, 128 mSDsluCounter, 46 mSDsCounter, 0 mSdLazyCounter, 409 mSolverCounterSat, 188 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.4s Time, 0 mProtectedPredicate, 0 mProtectedAction, 128 SdHoareTripleChecker+Valid, 43 SdHoareTripleChecker+Invalid, 597 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 188 IncrementalHoareTripleChecker+Valid, 409 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.5s IncrementalHoareTripleChecker+Time [2021-11-23 03:30:41,679 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [128 Valid, 43 Invalid, 597 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [188 Valid, 409 Invalid, 0 Unknown, 0 Unchecked, 0.5s Time] [2021-11-23 03:30:41,680 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 44 states. [2021-11-23 03:30:41,687 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 44 to 25. [2021-11-23 03:30:41,687 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 25 states, 24 states have (on average 1.25) internal successors, (30), 24 states have internal predecessors, (30), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:41,688 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 25 states to 25 states and 30 transitions. [2021-11-23 03:30:41,688 INFO L78 Accepts]: Start accepts. Automaton has 25 states and 30 transitions. Word has length 16 [2021-11-23 03:30:41,689 INFO L84 Accepts]: Finished accepts. word is rejected. [2021-11-23 03:30:41,689 INFO L470 AbstractCegarLoop]: Abstraction has 25 states and 30 transitions. [2021-11-23 03:30:41,689 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 40 states, 40 states have (on average 1.1) internal successors, (44), 40 states have internal predecessors, (44), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:41,689 INFO L276 IsEmpty]: Start isEmpty. Operand 25 states and 30 transitions. [2021-11-23 03:30:41,689 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 19 [2021-11-23 03:30:41,689 INFO L506 BasicCegarLoop]: Found error trace [2021-11-23 03:30:41,689 INFO L514 BasicCegarLoop]: trace histogram [4, 4, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2021-11-23 03:30:41,709 INFO L540 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (8)] Forceful destruction successful, exit code 0 [2021-11-23 03:30:41,890 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable10,8 /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:30:41,890 INFO L402 AbstractCegarLoop]: === Iteration 12 === Targeting ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION === [ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2021-11-23 03:30:41,890 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2021-11-23 03:30:41,891 INFO L85 PathProgramCache]: Analyzing trace with hash 2040615602, now seen corresponding path program 6 times [2021-11-23 03:30:41,891 INFO L121 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2021-11-23 03:30:41,891 INFO L333 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [117213746] [2021-11-23 03:30:41,891 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:30:41,891 INFO L126 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2021-11-23 03:30:41,913 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:30:42,416 INFO L134 CoverageAnalysis]: Checked inductivity of 20 backedges. 0 proven. 20 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:30:42,416 INFO L139 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2021-11-23 03:30:42,416 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [117213746] [2021-11-23 03:30:42,416 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [117213746] provided 0 perfect and 1 imperfect interpolant sequences [2021-11-23 03:30:42,416 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [831393337] [2021-11-23 03:30:42,417 INFO L93 rtionOrderModulation]: Changing assertion order to TERMS_WITH_SMALL_CONSTANTS_FIRST [2021-11-23 03:30:42,417 INFO L168 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:30:42,417 INFO L189 MonitoredProcess]: No working directory specified, using /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 [2021-11-23 03:30:42,418 INFO L229 MonitoredProcess]: Starting monitored process 9 with /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2021-11-23 03:30:42,425 INFO L327 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (9)] Waiting until timeout for monitored process [2021-11-23 03:30:42,464 INFO L228 tOrderPrioritization]: Assert order TERMS_WITH_SMALL_CONSTANTS_FIRST issued 0 check-sat command(s) [2021-11-23 03:30:42,465 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2021-11-23 03:30:42,466 INFO L263 TraceCheckSpWp]: Trace formula consists of 100 conjuncts, 49 conjunts are in the unsatisfiable core [2021-11-23 03:30:42,468 INFO L286 TraceCheckSpWp]: Computing forward predicates... [2021-11-23 03:30:43,814 INFO L134 CoverageAnalysis]: Checked inductivity of 20 backedges. 0 proven. 20 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:30:43,814 INFO L328 TraceCheckSpWp]: Computing backward predicates... [2021-11-23 03:30:44,882 INFO L134 CoverageAnalysis]: Checked inductivity of 20 backedges. 0 proven. 20 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:30:44,882 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleZ3 [831393337] provided 0 perfect and 2 imperfect interpolant sequences [2021-11-23 03:30:44,882 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [385360032] [2021-11-23 03:30:44,885 INFO L159 IcfgInterpreter]: Started Sifa with 11 locations of interest [2021-11-23 03:30:44,885 INFO L166 IcfgInterpreter]: Building call graph [2021-11-23 03:30:44,885 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2021-11-23 03:30:44,885 INFO L176 IcfgInterpreter]: Starting interpretation [2021-11-23 03:30:44,886 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2021-11-23 03:30:45,101 INFO L180 IcfgInterpreter]: Interpretation finished [2021-11-23 03:30:46,264 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '1694#(and (<= 4 |ULTIMATE.start_correct_version_~i~0#1|) (<= |ULTIMATE.start_correct_version_#res#1| 1) (<= 4 |ULTIMATE.start_student_version_~w#1|) (<= |ULTIMATE.start_main_~is_divisible1~0#1| 1) (<= 4 |ULTIMATE.start_correct_version_~w#1|) (<= 4 |ULTIMATE.start_student_version_#in~w#1|) (<= 0 |ULTIMATE.start_correct_version_~is_divisible~0#1|) (= ~true~0 1) (<= |ULTIMATE.start_correct_version_~is_divisible~0#1| 1) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| 0) (<= 4 |ULTIMATE.start_correct_version_#in~w#1|) (= ~false~0 0) (<= 0 |ULTIMATE.start_correct_version_#res#1|) (or (and (not (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|)) (= |ULTIMATE.start_student_version_~is_divisible~1#1| ~false~0)) (and (<= 1 |ULTIMATE.start_student_version_~is_divisible~1#1|) (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (<= |ULTIMATE.start_student_version_~is_divisible~1#1| 1))) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (= |#NULL.offset| 0) (= (ite (= |ULTIMATE.start_main_~is_divisible1~0#1| |ULTIMATE.start_main_~is_divisible2~0#1|) 1 0) |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (<= 0 |ULTIMATE.start_main_~is_divisible1~0#1|) (= |ULTIMATE.start_student_version_~is_divisible~1#1| |ULTIMATE.start_student_version_#res#1|) (<= 0 |#StackHeapBarrier|) (= |ULTIMATE.start_main_~is_divisible2~0#1| |ULTIMATE.start_student_version_#res#1|) (<= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (= |#NULL.base| 0))' at error location [2021-11-23 03:30:46,264 WARN L312 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2021-11-23 03:30:46,264 INFO L186 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2021-11-23 03:30:46,264 INFO L199 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [17, 17, 17] total 45 [2021-11-23 03:30:46,265 INFO L115 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [107488997] [2021-11-23 03:30:46,265 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2021-11-23 03:30:46,265 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 45 states [2021-11-23 03:30:46,265 INFO L103 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2021-11-23 03:30:46,266 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 45 interpolants. [2021-11-23 03:30:46,267 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=208, Invalid=2654, Unknown=0, NotChecked=0, Total=2862 [2021-11-23 03:30:46,267 INFO L87 Difference]: Start difference. First operand 25 states and 30 transitions. Second operand has 45 states, 45 states have (on average 1.0888888888888888) internal successors, (49), 45 states have internal predecessors, (49), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:55,224 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2021-11-23 03:30:55,224 INFO L93 Difference]: Finished difference Result 80 states and 90 transitions. [2021-11-23 03:30:55,225 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 46 states. [2021-11-23 03:30:55,225 INFO L78 Accepts]: Start accepts. Automaton has has 45 states, 45 states have (on average 1.0888888888888888) internal successors, (49), 45 states have internal predecessors, (49), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 18 [2021-11-23 03:30:55,225 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2021-11-23 03:30:55,226 INFO L225 Difference]: With dead ends: 80 [2021-11-23 03:30:55,226 INFO L226 Difference]: Without dead ends: 62 [2021-11-23 03:30:55,229 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 108 GetRequests, 16 SyntacticMatches, 1 SemanticMatches, 91 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 2291 ImplicationChecksByTransitivity, 11.2s TimeCoverageRelationStatistics Valid=818, Invalid=7738, Unknown=0, NotChecked=0, Total=8556 [2021-11-23 03:30:55,229 INFO L933 BasicCegarLoop]: 4 mSDtfsCounter, 167 mSDsluCounter, 80 mSDsCounter, 0 mSdLazyCounter, 601 mSolverCounterSat, 215 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.5s Time, 0 mProtectedPredicate, 0 mProtectedAction, 167 SdHoareTripleChecker+Valid, 77 SdHoareTripleChecker+Invalid, 816 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 215 IncrementalHoareTripleChecker+Valid, 601 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.6s IncrementalHoareTripleChecker+Time [2021-11-23 03:30:55,230 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [167 Valid, 77 Invalid, 816 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [215 Valid, 601 Invalid, 0 Unknown, 0 Unchecked, 0.6s Time] [2021-11-23 03:30:55,231 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 62 states. [2021-11-23 03:30:55,243 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 62 to 34. [2021-11-23 03:30:55,244 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 34 states, 33 states have (on average 1.2424242424242424) internal successors, (41), 33 states have internal predecessors, (41), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:55,245 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 34 states to 34 states and 41 transitions. [2021-11-23 03:30:55,245 INFO L78 Accepts]: Start accepts. Automaton has 34 states and 41 transitions. Word has length 18 [2021-11-23 03:30:55,245 INFO L84 Accepts]: Finished accepts. word is rejected. [2021-11-23 03:30:55,245 INFO L470 AbstractCegarLoop]: Abstraction has 34 states and 41 transitions. [2021-11-23 03:30:55,246 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 45 states, 45 states have (on average 1.0888888888888888) internal successors, (49), 45 states have internal predecessors, (49), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:30:55,246 INFO L276 IsEmpty]: Start isEmpty. Operand 34 states and 41 transitions. [2021-11-23 03:30:55,246 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 21 [2021-11-23 03:30:55,247 INFO L506 BasicCegarLoop]: Found error trace [2021-11-23 03:30:55,247 INFO L514 BasicCegarLoop]: trace histogram [5, 5, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2021-11-23 03:30:55,268 INFO L552 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (9)] Ended with exit code 0 [2021-11-23 03:30:55,453 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable11,9 /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:30:55,454 INFO L402 AbstractCegarLoop]: === Iteration 13 === Targeting ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION === [ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2021-11-23 03:30:55,454 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2021-11-23 03:30:55,454 INFO L85 PathProgramCache]: Analyzing trace with hash 1585528789, now seen corresponding path program 7 times [2021-11-23 03:30:55,454 INFO L121 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2021-11-23 03:30:55,454 INFO L333 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1617990109] [2021-11-23 03:30:55,454 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:30:55,455 INFO L126 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2021-11-23 03:30:55,466 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:30:56,005 INFO L134 CoverageAnalysis]: Checked inductivity of 30 backedges. 0 proven. 30 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:30:56,005 INFO L139 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2021-11-23 03:30:56,005 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1617990109] [2021-11-23 03:30:56,005 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1617990109] provided 0 perfect and 1 imperfect interpolant sequences [2021-11-23 03:30:56,006 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [938281558] [2021-11-23 03:30:56,006 INFO L93 rtionOrderModulation]: Changing assertion order to NOT_INCREMENTALLY [2021-11-23 03:30:56,006 INFO L168 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:30:56,006 INFO L189 MonitoredProcess]: No working directory specified, using /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 [2021-11-23 03:30:56,007 INFO L229 MonitoredProcess]: Starting monitored process 10 with /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2021-11-23 03:30:56,008 INFO L327 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (10)] Waiting until timeout for monitored process [2021-11-23 03:30:56,039 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:30:56,040 WARN L261 TraceCheckSpWp]: Trace formula consists of 106 conjuncts, 53 conjunts are in the unsatisfiable core [2021-11-23 03:30:56,042 INFO L286 TraceCheckSpWp]: Computing forward predicates... [2021-11-23 03:30:57,731 INFO L134 CoverageAnalysis]: Checked inductivity of 30 backedges. 0 proven. 30 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:30:57,731 INFO L328 TraceCheckSpWp]: Computing backward predicates... [2021-11-23 03:30:58,913 INFO L134 CoverageAnalysis]: Checked inductivity of 30 backedges. 0 proven. 30 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:30:58,913 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleZ3 [938281558] provided 0 perfect and 2 imperfect interpolant sequences [2021-11-23 03:30:58,913 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [647383827] [2021-11-23 03:30:58,915 INFO L159 IcfgInterpreter]: Started Sifa with 11 locations of interest [2021-11-23 03:30:58,916 INFO L166 IcfgInterpreter]: Building call graph [2021-11-23 03:30:58,916 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2021-11-23 03:30:58,916 INFO L176 IcfgInterpreter]: Starting interpretation [2021-11-23 03:30:58,916 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2021-11-23 03:30:59,107 INFO L180 IcfgInterpreter]: Interpretation finished [2021-11-23 03:31:00,206 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '2136#(and (<= 4 |ULTIMATE.start_correct_version_~i~0#1|) (<= |ULTIMATE.start_correct_version_#res#1| 1) (<= 4 |ULTIMATE.start_student_version_~w#1|) (<= |ULTIMATE.start_main_~is_divisible1~0#1| 1) (<= 4 |ULTIMATE.start_correct_version_~w#1|) (<= 4 |ULTIMATE.start_student_version_#in~w#1|) (<= 0 |ULTIMATE.start_correct_version_~is_divisible~0#1|) (= ~true~0 1) (<= |ULTIMATE.start_correct_version_~is_divisible~0#1| 1) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| 0) (<= 4 |ULTIMATE.start_correct_version_#in~w#1|) (= ~false~0 0) (<= 0 |ULTIMATE.start_correct_version_#res#1|) (or (and (not (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|)) (= |ULTIMATE.start_student_version_~is_divisible~1#1| ~false~0)) (and (<= 1 |ULTIMATE.start_student_version_~is_divisible~1#1|) (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (<= |ULTIMATE.start_student_version_~is_divisible~1#1| 1))) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (= |#NULL.offset| 0) (= (ite (= |ULTIMATE.start_main_~is_divisible1~0#1| |ULTIMATE.start_main_~is_divisible2~0#1|) 1 0) |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (<= 0 |ULTIMATE.start_main_~is_divisible1~0#1|) (= |ULTIMATE.start_student_version_~is_divisible~1#1| |ULTIMATE.start_student_version_#res#1|) (<= 0 |#StackHeapBarrier|) (= |ULTIMATE.start_main_~is_divisible2~0#1| |ULTIMATE.start_student_version_#res#1|) (<= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (= |#NULL.base| 0))' at error location [2021-11-23 03:31:00,206 WARN L312 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2021-11-23 03:31:00,206 INFO L186 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2021-11-23 03:31:00,206 INFO L199 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [19, 19, 19] total 51 [2021-11-23 03:31:00,206 INFO L115 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1543822059] [2021-11-23 03:31:00,206 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2021-11-23 03:31:00,207 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 51 states [2021-11-23 03:31:00,207 INFO L103 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2021-11-23 03:31:00,207 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 51 interpolants. [2021-11-23 03:31:00,208 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=235, Invalid=3305, Unknown=0, NotChecked=0, Total=3540 [2021-11-23 03:31:00,208 INFO L87 Difference]: Start difference. First operand 34 states and 41 transitions. Second operand has 51 states, 51 states have (on average 1.0784313725490196) internal successors, (55), 51 states have internal predecessors, (55), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:31:10,261 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2021-11-23 03:31:10,262 INFO L93 Difference]: Finished difference Result 92 states and 106 transitions. [2021-11-23 03:31:10,262 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 51 states. [2021-11-23 03:31:10,262 INFO L78 Accepts]: Start accepts. Automaton has has 51 states, 51 states have (on average 1.0784313725490196) internal successors, (55), 51 states have internal predecessors, (55), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 20 [2021-11-23 03:31:10,262 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2021-11-23 03:31:10,263 INFO L225 Difference]: With dead ends: 92 [2021-11-23 03:31:10,263 INFO L226 Difference]: Without dead ends: 73 [2021-11-23 03:31:10,266 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 120 GetRequests, 18 SyntacticMatches, 1 SemanticMatches, 101 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 2867 ImplicationChecksByTransitivity, 12.5s TimeCoverageRelationStatistics Valid=930, Invalid=9576, Unknown=0, NotChecked=0, Total=10506 [2021-11-23 03:31:10,267 INFO L933 BasicCegarLoop]: 2 mSDtfsCounter, 212 mSDsluCounter, 74 mSDsCounter, 0 mSdLazyCounter, 778 mSolverCounterSat, 290 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.6s Time, 0 mProtectedPredicate, 0 mProtectedAction, 212 SdHoareTripleChecker+Valid, 70 SdHoareTripleChecker+Invalid, 1068 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 290 IncrementalHoareTripleChecker+Valid, 778 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.7s IncrementalHoareTripleChecker+Time [2021-11-23 03:31:10,267 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [212 Valid, 70 Invalid, 1068 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [290 Valid, 778 Invalid, 0 Unknown, 0 Unchecked, 0.7s Time] [2021-11-23 03:31:10,268 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 73 states. [2021-11-23 03:31:10,289 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 73 to 44. [2021-11-23 03:31:10,290 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 44 states, 43 states have (on average 1.255813953488372) internal successors, (54), 43 states have internal predecessors, (54), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:31:10,290 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 44 states to 44 states and 54 transitions. [2021-11-23 03:31:10,290 INFO L78 Accepts]: Start accepts. Automaton has 44 states and 54 transitions. Word has length 20 [2021-11-23 03:31:10,291 INFO L84 Accepts]: Finished accepts. word is rejected. [2021-11-23 03:31:10,291 INFO L470 AbstractCegarLoop]: Abstraction has 44 states and 54 transitions. [2021-11-23 03:31:10,291 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 51 states, 51 states have (on average 1.0784313725490196) internal successors, (55), 51 states have internal predecessors, (55), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:31:10,291 INFO L276 IsEmpty]: Start isEmpty. Operand 44 states and 54 transitions. [2021-11-23 03:31:10,292 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 22 [2021-11-23 03:31:10,292 INFO L506 BasicCegarLoop]: Found error trace [2021-11-23 03:31:10,292 INFO L514 BasicCegarLoop]: trace histogram [8, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2021-11-23 03:31:10,316 INFO L540 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (10)] Forceful destruction successful, exit code 0 [2021-11-23 03:31:10,497 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: 10 /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true,SelfDestructingSolverStorable12 [2021-11-23 03:31:10,498 INFO L402 AbstractCegarLoop]: === Iteration 14 === Targeting ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION === [ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2021-11-23 03:31:10,498 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2021-11-23 03:31:10,498 INFO L85 PathProgramCache]: Analyzing trace with hash 152487921, now seen corresponding path program 8 times [2021-11-23 03:31:10,498 INFO L121 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2021-11-23 03:31:10,498 INFO L333 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [19584451] [2021-11-23 03:31:10,498 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:31:10,499 INFO L126 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2021-11-23 03:31:10,506 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:31:10,951 INFO L134 CoverageAnalysis]: Checked inductivity of 42 backedges. 21 proven. 21 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:31:10,952 INFO L139 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2021-11-23 03:31:10,952 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [19584451] [2021-11-23 03:31:10,952 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [19584451] provided 0 perfect and 1 imperfect interpolant sequences [2021-11-23 03:31:10,952 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1639943691] [2021-11-23 03:31:10,952 INFO L93 rtionOrderModulation]: Changing assertion order to OUTSIDE_LOOP_FIRST2 [2021-11-23 03:31:10,952 INFO L168 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:31:10,952 INFO L189 MonitoredProcess]: No working directory specified, using /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 [2021-11-23 03:31:10,953 INFO L229 MonitoredProcess]: Starting monitored process 11 with /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2021-11-23 03:31:10,973 INFO L327 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (11)] Waiting until timeout for monitored process [2021-11-23 03:31:11,000 INFO L228 tOrderPrioritization]: Assert order OUTSIDE_LOOP_FIRST2 issued 5 check-sat command(s) [2021-11-23 03:31:11,000 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2021-11-23 03:31:11,001 INFO L263 TraceCheckSpWp]: Trace formula consists of 109 conjuncts, 14 conjunts are in the unsatisfiable core [2021-11-23 03:31:11,003 INFO L286 TraceCheckSpWp]: Computing forward predicates... [2021-11-23 03:31:11,333 INFO L134 CoverageAnalysis]: Checked inductivity of 42 backedges. 6 proven. 26 refuted. 0 times theorem prover too weak. 10 trivial. 0 not checked. [2021-11-23 03:31:11,333 INFO L328 TraceCheckSpWp]: Computing backward predicates... [2021-11-23 03:31:11,645 INFO L134 CoverageAnalysis]: Checked inductivity of 42 backedges. 26 proven. 6 refuted. 0 times theorem prover too weak. 10 trivial. 0 not checked. [2021-11-23 03:31:11,645 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1639943691] provided 0 perfect and 2 imperfect interpolant sequences [2021-11-23 03:31:11,645 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [776299042] [2021-11-23 03:31:11,647 INFO L159 IcfgInterpreter]: Started Sifa with 11 locations of interest [2021-11-23 03:31:11,647 INFO L166 IcfgInterpreter]: Building call graph [2021-11-23 03:31:11,648 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2021-11-23 03:31:11,648 INFO L176 IcfgInterpreter]: Starting interpretation [2021-11-23 03:31:11,648 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2021-11-23 03:31:11,800 INFO L180 IcfgInterpreter]: Interpretation finished [2021-11-23 03:31:12,751 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '2621#(and (<= 4 |ULTIMATE.start_correct_version_~i~0#1|) (<= |ULTIMATE.start_correct_version_#res#1| 1) (<= 4 |ULTIMATE.start_student_version_~w#1|) (<= |ULTIMATE.start_main_~is_divisible1~0#1| 1) (<= 4 |ULTIMATE.start_correct_version_~w#1|) (<= 4 |ULTIMATE.start_student_version_#in~w#1|) (<= 0 |ULTIMATE.start_correct_version_~is_divisible~0#1|) (<= |ULTIMATE.start_correct_version_~is_divisible~0#1| 1) (<= ~false~0 0) (<= |#NULL.offset| 0) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| 0) (<= 0 ~false~0) (<= 4 |ULTIMATE.start_correct_version_#in~w#1|) (<= 1 ~true~0) (<= 0 |ULTIMATE.start_correct_version_#res#1|) (or (and (not (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|)) (= |ULTIMATE.start_student_version_~is_divisible~1#1| ~false~0)) (and (<= 1 |ULTIMATE.start_student_version_~is_divisible~1#1|) (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (<= |ULTIMATE.start_student_version_~is_divisible~1#1| 1))) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (= (ite (= |ULTIMATE.start_main_~is_divisible1~0#1| |ULTIMATE.start_main_~is_divisible2~0#1|) 1 0) |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (<= 0 |ULTIMATE.start_main_~is_divisible1~0#1|) (<= ~true~0 1) (= |ULTIMATE.start_student_version_~is_divisible~1#1| |ULTIMATE.start_student_version_#res#1|) (<= 0 |#NULL.offset|) (<= 0 |#StackHeapBarrier|) (= |ULTIMATE.start_main_~is_divisible2~0#1| |ULTIMATE.start_student_version_#res#1|) (<= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (= |#NULL.base| 0))' at error location [2021-11-23 03:31:12,751 WARN L312 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2021-11-23 03:31:12,751 INFO L186 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2021-11-23 03:31:12,751 INFO L199 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [18, 13, 13] total 38 [2021-11-23 03:31:12,751 INFO L115 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [400959047] [2021-11-23 03:31:12,751 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2021-11-23 03:31:12,752 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 38 states [2021-11-23 03:31:12,752 INFO L103 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2021-11-23 03:31:12,753 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 38 interpolants. [2021-11-23 03:31:12,753 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=309, Invalid=1853, Unknown=0, NotChecked=0, Total=2162 [2021-11-23 03:31:12,754 INFO L87 Difference]: Start difference. First operand 44 states and 54 transitions. Second operand has 38 states, 38 states have (on average 1.2105263157894737) internal successors, (46), 38 states have internal predecessors, (46), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:31:13,939 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2021-11-23 03:31:13,940 INFO L93 Difference]: Finished difference Result 76 states and 90 transitions. [2021-11-23 03:31:13,940 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 31 states. [2021-11-23 03:31:13,940 INFO L78 Accepts]: Start accepts. Automaton has has 38 states, 38 states have (on average 1.2105263157894737) internal successors, (46), 38 states have internal predecessors, (46), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 21 [2021-11-23 03:31:13,940 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2021-11-23 03:31:13,941 INFO L225 Difference]: With dead ends: 76 [2021-11-23 03:31:13,941 INFO L226 Difference]: Without dead ends: 72 [2021-11-23 03:31:13,942 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 103 GetRequests, 32 SyntacticMatches, 2 SemanticMatches, 69 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 1371 ImplicationChecksByTransitivity, 2.6s TimeCoverageRelationStatistics Valid=1135, Invalid=3835, Unknown=0, NotChecked=0, Total=4970 [2021-11-23 03:31:13,943 INFO L933 BasicCegarLoop]: 7 mSDtfsCounter, 82 mSDsluCounter, 61 mSDsCounter, 0 mSdLazyCounter, 247 mSolverCounterSat, 70 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.1s Time, 0 mProtectedPredicate, 0 mProtectedAction, 82 SdHoareTripleChecker+Valid, 46 SdHoareTripleChecker+Invalid, 317 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 70 IncrementalHoareTripleChecker+Valid, 247 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.2s IncrementalHoareTripleChecker+Time [2021-11-23 03:31:13,943 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [82 Valid, 46 Invalid, 317 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [70 Valid, 247 Invalid, 0 Unknown, 0 Unchecked, 0.2s Time] [2021-11-23 03:31:13,944 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 72 states. [2021-11-23 03:31:13,958 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 72 to 29. [2021-11-23 03:31:13,958 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 29 states, 28 states have (on average 1.1428571428571428) internal successors, (32), 28 states have internal predecessors, (32), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:31:13,959 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 29 states to 29 states and 32 transitions. [2021-11-23 03:31:13,959 INFO L78 Accepts]: Start accepts. Automaton has 29 states and 32 transitions. Word has length 21 [2021-11-23 03:31:13,959 INFO L84 Accepts]: Finished accepts. word is rejected. [2021-11-23 03:31:13,959 INFO L470 AbstractCegarLoop]: Abstraction has 29 states and 32 transitions. [2021-11-23 03:31:13,960 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 38 states, 38 states have (on average 1.2105263157894737) internal successors, (46), 38 states have internal predecessors, (46), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:31:13,960 INFO L276 IsEmpty]: Start isEmpty. Operand 29 states and 32 transitions. [2021-11-23 03:31:13,960 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 23 [2021-11-23 03:31:13,961 INFO L506 BasicCegarLoop]: Found error trace [2021-11-23 03:31:13,961 INFO L514 BasicCegarLoop]: trace histogram [6, 6, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2021-11-23 03:31:13,990 INFO L540 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (11)] Forceful destruction successful, exit code 0 [2021-11-23 03:31:14,173 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: 11 /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true,SelfDestructingSolverStorable13 [2021-11-23 03:31:14,174 INFO L402 AbstractCegarLoop]: === Iteration 15 === Targeting ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION === [ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2021-11-23 03:31:14,174 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2021-11-23 03:31:14,174 INFO L85 PathProgramCache]: Analyzing trace with hash 789435922, now seen corresponding path program 9 times [2021-11-23 03:31:14,174 INFO L121 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2021-11-23 03:31:14,174 INFO L333 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1734753609] [2021-11-23 03:31:14,175 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:31:14,175 INFO L126 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2021-11-23 03:31:14,187 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:31:14,770 INFO L134 CoverageAnalysis]: Checked inductivity of 42 backedges. 0 proven. 42 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:31:14,771 INFO L139 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2021-11-23 03:31:14,771 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1734753609] [2021-11-23 03:31:14,771 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1734753609] provided 0 perfect and 1 imperfect interpolant sequences [2021-11-23 03:31:14,771 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1678434848] [2021-11-23 03:31:14,771 INFO L93 rtionOrderModulation]: Changing assertion order to TERMS_WITH_SMALL_CONSTANTS_FIRST [2021-11-23 03:31:14,771 INFO L168 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:31:14,771 INFO L189 MonitoredProcess]: No working directory specified, using /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 [2021-11-23 03:31:14,772 INFO L229 MonitoredProcess]: Starting monitored process 12 with /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2021-11-23 03:31:14,773 INFO L327 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (12)] Waiting until timeout for monitored process [2021-11-23 03:31:14,813 INFO L228 tOrderPrioritization]: Assert order TERMS_WITH_SMALL_CONSTANTS_FIRST issued 0 check-sat command(s) [2021-11-23 03:31:14,813 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2021-11-23 03:31:14,815 WARN L261 TraceCheckSpWp]: Trace formula consists of 112 conjuncts, 57 conjunts are in the unsatisfiable core [2021-11-23 03:31:14,817 INFO L286 TraceCheckSpWp]: Computing forward predicates... [2021-11-23 03:31:16,370 INFO L134 CoverageAnalysis]: Checked inductivity of 42 backedges. 0 proven. 42 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:31:16,370 INFO L328 TraceCheckSpWp]: Computing backward predicates... [2021-11-23 03:31:17,631 INFO L134 CoverageAnalysis]: Checked inductivity of 42 backedges. 0 proven. 42 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:31:17,631 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1678434848] provided 0 perfect and 2 imperfect interpolant sequences [2021-11-23 03:31:17,631 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [1721111901] [2021-11-23 03:31:17,633 INFO L159 IcfgInterpreter]: Started Sifa with 11 locations of interest [2021-11-23 03:31:17,633 INFO L166 IcfgInterpreter]: Building call graph [2021-11-23 03:31:17,633 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2021-11-23 03:31:17,633 INFO L176 IcfgInterpreter]: Starting interpretation [2021-11-23 03:31:17,634 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2021-11-23 03:31:17,766 INFO L180 IcfgInterpreter]: Interpretation finished [2021-11-23 03:31:18,967 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '3043#(and (<= 4 |ULTIMATE.start_correct_version_~i~0#1|) (<= |ULTIMATE.start_correct_version_#res#1| 1) (<= 4 |ULTIMATE.start_student_version_~w#1|) (<= |ULTIMATE.start_main_~is_divisible1~0#1| 1) (<= 4 |ULTIMATE.start_correct_version_~w#1|) (<= 4 |ULTIMATE.start_student_version_#in~w#1|) (<= 0 |ULTIMATE.start_correct_version_~is_divisible~0#1|) (= ~true~0 1) (<= |ULTIMATE.start_correct_version_~is_divisible~0#1| 1) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| 0) (<= 4 |ULTIMATE.start_correct_version_#in~w#1|) (= ~false~0 0) (<= 0 |ULTIMATE.start_correct_version_#res#1|) (or (and (not (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|)) (= |ULTIMATE.start_student_version_~is_divisible~1#1| ~false~0)) (and (<= 1 |ULTIMATE.start_student_version_~is_divisible~1#1|) (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (<= |ULTIMATE.start_student_version_~is_divisible~1#1| 1))) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (= |#NULL.offset| 0) (= (ite (= |ULTIMATE.start_main_~is_divisible1~0#1| |ULTIMATE.start_main_~is_divisible2~0#1|) 1 0) |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (<= 0 |ULTIMATE.start_main_~is_divisible1~0#1|) (= |ULTIMATE.start_student_version_~is_divisible~1#1| |ULTIMATE.start_student_version_#res#1|) (<= 0 |#StackHeapBarrier|) (= |ULTIMATE.start_main_~is_divisible2~0#1| |ULTIMATE.start_student_version_#res#1|) (<= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (= |#NULL.base| 0))' at error location [2021-11-23 03:31:18,968 WARN L312 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2021-11-23 03:31:18,968 INFO L186 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2021-11-23 03:31:18,968 INFO L199 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [21, 21, 21] total 57 [2021-11-23 03:31:18,969 INFO L115 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [247135079] [2021-11-23 03:31:18,969 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2021-11-23 03:31:18,970 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 57 states [2021-11-23 03:31:18,970 INFO L103 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2021-11-23 03:31:18,971 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 57 interpolants. [2021-11-23 03:31:18,972 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=262, Invalid=4028, Unknown=0, NotChecked=0, Total=4290 [2021-11-23 03:31:18,973 INFO L87 Difference]: Start difference. First operand 29 states and 32 transitions. Second operand has 57 states, 57 states have (on average 1.0701754385964912) internal successors, (61), 57 states have internal predecessors, (61), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:31:30,100 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2021-11-23 03:31:30,100 INFO L93 Difference]: Finished difference Result 90 states and 101 transitions. [2021-11-23 03:31:30,101 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 52 states. [2021-11-23 03:31:30,101 INFO L78 Accepts]: Start accepts. Automaton has has 57 states, 57 states have (on average 1.0701754385964912) internal successors, (61), 57 states have internal predecessors, (61), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 22 [2021-11-23 03:31:30,102 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2021-11-23 03:31:30,103 INFO L225 Difference]: With dead ends: 90 [2021-11-23 03:31:30,103 INFO L226 Difference]: Without dead ends: 72 [2021-11-23 03:31:30,107 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 128 GetRequests, 20 SyntacticMatches, 1 SemanticMatches, 107 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 3236 ImplicationChecksByTransitivity, 13.6s TimeCoverageRelationStatistics Valid=946, Invalid=10826, Unknown=0, NotChecked=0, Total=11772 [2021-11-23 03:31:30,108 INFO L933 BasicCegarLoop]: 2 mSDtfsCounter, 129 mSDsluCounter, 84 mSDsCounter, 0 mSdLazyCounter, 991 mSolverCounterSat, 276 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.7s Time, 0 mProtectedPredicate, 0 mProtectedAction, 129 SdHoareTripleChecker+Valid, 79 SdHoareTripleChecker+Invalid, 1267 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 276 IncrementalHoareTripleChecker+Valid, 991 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.8s IncrementalHoareTripleChecker+Time [2021-11-23 03:31:30,108 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [129 Valid, 79 Invalid, 1267 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [276 Valid, 991 Invalid, 0 Unknown, 0 Unchecked, 0.8s Time] [2021-11-23 03:31:30,109 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 72 states. [2021-11-23 03:31:30,124 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 72 to 29. [2021-11-23 03:31:30,125 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 29 states, 28 states have (on average 1.1071428571428572) internal successors, (31), 28 states have internal predecessors, (31), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:31:30,125 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 29 states to 29 states and 31 transitions. [2021-11-23 03:31:30,126 INFO L78 Accepts]: Start accepts. Automaton has 29 states and 31 transitions. Word has length 22 [2021-11-23 03:31:30,126 INFO L84 Accepts]: Finished accepts. word is rejected. [2021-11-23 03:31:30,126 INFO L470 AbstractCegarLoop]: Abstraction has 29 states and 31 transitions. [2021-11-23 03:31:30,126 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 57 states, 57 states have (on average 1.0701754385964912) internal successors, (61), 57 states have internal predecessors, (61), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:31:30,126 INFO L276 IsEmpty]: Start isEmpty. Operand 29 states and 31 transitions. [2021-11-23 03:31:30,127 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 25 [2021-11-23 03:31:30,127 INFO L506 BasicCegarLoop]: Found error trace [2021-11-23 03:31:30,127 INFO L514 BasicCegarLoop]: trace histogram [7, 7, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2021-11-23 03:31:30,148 INFO L540 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (12)] Forceful destruction successful, exit code 0 [2021-11-23 03:31:30,329 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: 12 /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true,SelfDestructingSolverStorable14 [2021-11-23 03:31:30,330 INFO L402 AbstractCegarLoop]: === Iteration 16 === Targeting ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION === [ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2021-11-23 03:31:30,330 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2021-11-23 03:31:30,330 INFO L85 PathProgramCache]: Analyzing trace with hash -381213067, now seen corresponding path program 10 times [2021-11-23 03:31:30,330 INFO L121 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2021-11-23 03:31:30,330 INFO L333 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1797845077] [2021-11-23 03:31:30,330 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:31:30,330 INFO L126 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2021-11-23 03:31:30,343 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:31:30,984 INFO L134 CoverageAnalysis]: Checked inductivity of 56 backedges. 0 proven. 56 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:31:30,985 INFO L139 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2021-11-23 03:31:30,985 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1797845077] [2021-11-23 03:31:30,985 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1797845077] provided 0 perfect and 1 imperfect interpolant sequences [2021-11-23 03:31:30,985 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [572874093] [2021-11-23 03:31:30,985 INFO L93 rtionOrderModulation]: Changing assertion order to NOT_INCREMENTALLY [2021-11-23 03:31:30,985 INFO L168 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:31:30,986 INFO L189 MonitoredProcess]: No working directory specified, using /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 [2021-11-23 03:31:30,986 INFO L229 MonitoredProcess]: Starting monitored process 13 with /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2021-11-23 03:31:30,987 INFO L327 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (13)] Waiting until timeout for monitored process [2021-11-23 03:31:31,022 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:31:31,023 WARN L261 TraceCheckSpWp]: Trace formula consists of 118 conjuncts, 61 conjunts are in the unsatisfiable core [2021-11-23 03:31:31,025 INFO L286 TraceCheckSpWp]: Computing forward predicates... [2021-11-23 03:31:32,813 INFO L134 CoverageAnalysis]: Checked inductivity of 56 backedges. 0 proven. 56 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:31:32,813 INFO L328 TraceCheckSpWp]: Computing backward predicates... [2021-11-23 03:31:34,330 INFO L134 CoverageAnalysis]: Checked inductivity of 56 backedges. 0 proven. 56 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:31:34,330 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleZ3 [572874093] provided 0 perfect and 2 imperfect interpolant sequences [2021-11-23 03:31:34,330 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [1111482257] [2021-11-23 03:31:34,332 INFO L159 IcfgInterpreter]: Started Sifa with 11 locations of interest [2021-11-23 03:31:34,332 INFO L166 IcfgInterpreter]: Building call graph [2021-11-23 03:31:34,333 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2021-11-23 03:31:34,333 INFO L176 IcfgInterpreter]: Starting interpretation [2021-11-23 03:31:34,333 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2021-11-23 03:31:34,519 INFO L180 IcfgInterpreter]: Interpretation finished [2021-11-23 03:31:35,988 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '3547#(and (<= 4 |ULTIMATE.start_correct_version_~i~0#1|) (<= |ULTIMATE.start_correct_version_#res#1| 1) (<= 4 |ULTIMATE.start_student_version_~w#1|) (<= |ULTIMATE.start_main_~is_divisible1~0#1| 1) (<= 4 |ULTIMATE.start_correct_version_~w#1|) (<= 4 |ULTIMATE.start_student_version_#in~w#1|) (<= 0 |ULTIMATE.start_correct_version_~is_divisible~0#1|) (<= |ULTIMATE.start_correct_version_~is_divisible~0#1| 1) (<= ~false~0 0) (<= |#NULL.offset| 0) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| 0) (<= 0 ~false~0) (<= 4 |ULTIMATE.start_correct_version_#in~w#1|) (<= 1 ~true~0) (<= 0 |ULTIMATE.start_correct_version_#res#1|) (or (and (not (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|)) (= |ULTIMATE.start_student_version_~is_divisible~1#1| ~false~0)) (and (<= 1 |ULTIMATE.start_student_version_~is_divisible~1#1|) (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (<= |ULTIMATE.start_student_version_~is_divisible~1#1| 1))) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (= (ite (= |ULTIMATE.start_main_~is_divisible1~0#1| |ULTIMATE.start_main_~is_divisible2~0#1|) 1 0) |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (<= 0 |ULTIMATE.start_main_~is_divisible1~0#1|) (<= ~true~0 1) (= |ULTIMATE.start_student_version_~is_divisible~1#1| |ULTIMATE.start_student_version_#res#1|) (<= 0 |#NULL.offset|) (<= 0 |#StackHeapBarrier|) (= |ULTIMATE.start_main_~is_divisible2~0#1| |ULTIMATE.start_student_version_#res#1|) (<= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (= |#NULL.base| 0))' at error location [2021-11-23 03:31:35,988 WARN L312 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2021-11-23 03:31:35,988 INFO L186 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2021-11-23 03:31:35,988 INFO L199 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [23, 23, 23] total 63 [2021-11-23 03:31:35,988 INFO L115 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [122436296] [2021-11-23 03:31:35,988 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2021-11-23 03:31:35,989 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 63 states [2021-11-23 03:31:35,989 INFO L103 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2021-11-23 03:31:35,989 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 63 interpolants. [2021-11-23 03:31:35,990 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=289, Invalid=4823, Unknown=0, NotChecked=0, Total=5112 [2021-11-23 03:31:35,990 INFO L87 Difference]: Start difference. First operand 29 states and 31 transitions. Second operand has 63 states, 63 states have (on average 1.0634920634920635) internal successors, (67), 63 states have internal predecessors, (67), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:31:47,370 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2021-11-23 03:31:47,370 INFO L93 Difference]: Finished difference Result 82 states and 93 transitions. [2021-11-23 03:31:47,371 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 55 states. [2021-11-23 03:31:47,371 INFO L78 Accepts]: Start accepts. Automaton has has 63 states, 63 states have (on average 1.0634920634920635) internal successors, (67), 63 states have internal predecessors, (67), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 24 [2021-11-23 03:31:47,371 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2021-11-23 03:31:47,371 INFO L225 Difference]: With dead ends: 82 [2021-11-23 03:31:47,372 INFO L226 Difference]: Without dead ends: 65 [2021-11-23 03:31:47,373 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 138 GetRequests, 22 SyntacticMatches, 1 SemanticMatches, 115 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 3764 ImplicationChecksByTransitivity, 14.6s TimeCoverageRelationStatistics Valid=1005, Invalid=12567, Unknown=0, NotChecked=0, Total=13572 [2021-11-23 03:31:47,373 INFO L933 BasicCegarLoop]: 2 mSDtfsCounter, 125 mSDsluCounter, 74 mSDsCounter, 0 mSdLazyCounter, 978 mSolverCounterSat, 344 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.7s Time, 0 mProtectedPredicate, 0 mProtectedAction, 125 SdHoareTripleChecker+Valid, 67 SdHoareTripleChecker+Invalid, 1322 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 344 IncrementalHoareTripleChecker+Valid, 978 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.9s IncrementalHoareTripleChecker+Time [2021-11-23 03:31:47,373 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [125 Valid, 67 Invalid, 1322 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [344 Valid, 978 Invalid, 0 Unknown, 0 Unchecked, 0.9s Time] [2021-11-23 03:31:47,374 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 65 states. [2021-11-23 03:31:47,395 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 65 to 27. [2021-11-23 03:31:47,395 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 27 states, 26 states have (on average 1.0769230769230769) internal successors, (28), 26 states have internal predecessors, (28), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:31:47,396 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 27 states to 27 states and 28 transitions. [2021-11-23 03:31:47,396 INFO L78 Accepts]: Start accepts. Automaton has 27 states and 28 transitions. Word has length 24 [2021-11-23 03:31:47,396 INFO L84 Accepts]: Finished accepts. word is rejected. [2021-11-23 03:31:47,397 INFO L470 AbstractCegarLoop]: Abstraction has 27 states and 28 transitions. [2021-11-23 03:31:47,397 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 63 states, 63 states have (on average 1.0634920634920635) internal successors, (67), 63 states have internal predecessors, (67), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:31:47,397 INFO L276 IsEmpty]: Start isEmpty. Operand 27 states and 28 transitions. [2021-11-23 03:31:47,398 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 27 [2021-11-23 03:31:47,398 INFO L506 BasicCegarLoop]: Found error trace [2021-11-23 03:31:47,398 INFO L514 BasicCegarLoop]: trace histogram [8, 8, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2021-11-23 03:31:47,419 INFO L540 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (13)] Forceful destruction successful, exit code 0 [2021-11-23 03:31:47,601 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable15,13 /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:31:47,602 INFO L402 AbstractCegarLoop]: === Iteration 17 === Targeting ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION === [ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2021-11-23 03:31:47,602 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2021-11-23 03:31:47,602 INFO L85 PathProgramCache]: Analyzing trace with hash 1864319346, now seen corresponding path program 11 times [2021-11-23 03:31:47,602 INFO L121 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2021-11-23 03:31:47,602 INFO L333 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1624766454] [2021-11-23 03:31:47,602 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:31:47,602 INFO L126 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2021-11-23 03:31:47,617 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:31:48,328 INFO L134 CoverageAnalysis]: Checked inductivity of 72 backedges. 0 proven. 72 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:31:48,328 INFO L139 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2021-11-23 03:31:48,328 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1624766454] [2021-11-23 03:31:48,328 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1624766454] provided 0 perfect and 1 imperfect interpolant sequences [2021-11-23 03:31:48,329 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1063562383] [2021-11-23 03:31:48,329 INFO L93 rtionOrderModulation]: Changing assertion order to OUTSIDE_LOOP_FIRST2 [2021-11-23 03:31:48,329 INFO L168 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:31:48,329 INFO L189 MonitoredProcess]: No working directory specified, using /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 [2021-11-23 03:31:48,330 INFO L229 MonitoredProcess]: Starting monitored process 14 with /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2021-11-23 03:31:48,331 INFO L327 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (14)] Waiting until timeout for monitored process [2021-11-23 03:31:48,368 INFO L228 tOrderPrioritization]: Assert order OUTSIDE_LOOP_FIRST2 issued 5 check-sat command(s) [2021-11-23 03:31:48,368 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2021-11-23 03:31:48,377 WARN L261 TraceCheckSpWp]: Trace formula consists of 124 conjuncts, 67 conjunts are in the unsatisfiable core [2021-11-23 03:31:48,379 INFO L286 TraceCheckSpWp]: Computing forward predicates... [2021-11-23 03:31:50,692 INFO L134 CoverageAnalysis]: Checked inductivity of 72 backedges. 0 proven. 72 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:31:50,692 INFO L328 TraceCheckSpWp]: Computing backward predicates... [2021-11-23 03:31:52,776 INFO L134 CoverageAnalysis]: Checked inductivity of 72 backedges. 0 proven. 72 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:31:52,777 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1063562383] provided 0 perfect and 2 imperfect interpolant sequences [2021-11-23 03:31:52,777 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [907942527] [2021-11-23 03:31:52,778 INFO L159 IcfgInterpreter]: Started Sifa with 11 locations of interest [2021-11-23 03:31:52,779 INFO L166 IcfgInterpreter]: Building call graph [2021-11-23 03:31:52,779 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2021-11-23 03:31:52,779 INFO L176 IcfgInterpreter]: Starting interpretation [2021-11-23 03:31:52,779 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2021-11-23 03:31:52,958 INFO L180 IcfgInterpreter]: Interpretation finished [2021-11-23 03:31:54,234 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '4057#(and (<= 4 |ULTIMATE.start_correct_version_~i~0#1|) (<= |ULTIMATE.start_correct_version_#res#1| 1) (<= 4 |ULTIMATE.start_student_version_~w#1|) (<= |ULTIMATE.start_main_~is_divisible1~0#1| 1) (<= 4 |ULTIMATE.start_correct_version_~w#1|) (<= 4 |ULTIMATE.start_student_version_#in~w#1|) (<= 0 |ULTIMATE.start_correct_version_~is_divisible~0#1|) (= ~true~0 1) (<= |ULTIMATE.start_correct_version_~is_divisible~0#1| 1) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| 0) (<= 4 |ULTIMATE.start_correct_version_#in~w#1|) (= ~false~0 0) (<= 0 |ULTIMATE.start_correct_version_#res#1|) (or (and (not (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|)) (= |ULTIMATE.start_student_version_~is_divisible~1#1| ~false~0)) (and (<= 1 |ULTIMATE.start_student_version_~is_divisible~1#1|) (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (<= |ULTIMATE.start_student_version_~is_divisible~1#1| 1))) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (= |#NULL.offset| 0) (= (ite (= |ULTIMATE.start_main_~is_divisible1~0#1| |ULTIMATE.start_main_~is_divisible2~0#1|) 1 0) |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (<= 0 |ULTIMATE.start_main_~is_divisible1~0#1|) (= |ULTIMATE.start_student_version_~is_divisible~1#1| |ULTIMATE.start_student_version_#res#1|) (<= 0 |#StackHeapBarrier|) (= |ULTIMATE.start_main_~is_divisible2~0#1| |ULTIMATE.start_student_version_#res#1|) (<= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (= |#NULL.base| 0))' at error location [2021-11-23 03:31:54,235 WARN L312 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2021-11-23 03:31:54,235 INFO L186 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2021-11-23 03:31:54,235 INFO L199 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [25, 25, 25] total 70 [2021-11-23 03:31:54,235 INFO L115 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1174318314] [2021-11-23 03:31:54,235 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2021-11-23 03:31:54,235 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 70 states [2021-11-23 03:31:54,236 INFO L103 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2021-11-23 03:31:54,236 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 70 interpolants. [2021-11-23 03:31:54,236 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=319, Invalid=5843, Unknown=0, NotChecked=0, Total=6162 [2021-11-23 03:31:54,237 INFO L87 Difference]: Start difference. First operand 27 states and 28 transitions. Second operand has 70 states, 70 states have (on average 1.0571428571428572) internal successors, (74), 70 states have internal predecessors, (74), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:32:04,975 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2021-11-23 03:32:04,975 INFO L93 Difference]: Finished difference Result 91 states and 105 transitions. [2021-11-23 03:32:04,976 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 64 states. [2021-11-23 03:32:04,976 INFO L78 Accepts]: Start accepts. Automaton has has 70 states, 70 states have (on average 1.0571428571428572) internal successors, (74), 70 states have internal predecessors, (74), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 26 [2021-11-23 03:32:04,976 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2021-11-23 03:32:04,977 INFO L225 Difference]: With dead ends: 91 [2021-11-23 03:32:04,977 INFO L226 Difference]: Without dead ends: 69 [2021-11-23 03:32:04,979 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 154 GetRequests, 23 SyntacticMatches, 1 SemanticMatches, 130 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 4907 ImplicationChecksByTransitivity, 14.3s TimeCoverageRelationStatistics Valid=1218, Invalid=16074, Unknown=0, NotChecked=0, Total=17292 [2021-11-23 03:32:04,980 INFO L933 BasicCegarLoop]: 2 mSDtfsCounter, 158 mSDsluCounter, 92 mSDsCounter, 0 mSdLazyCounter, 1321 mSolverCounterSat, 416 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.9s Time, 0 mProtectedPredicate, 0 mProtectedAction, 158 SdHoareTripleChecker+Valid, 89 SdHoareTripleChecker+Invalid, 1737 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 416 IncrementalHoareTripleChecker+Valid, 1321 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 1.0s IncrementalHoareTripleChecker+Time [2021-11-23 03:32:04,980 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [158 Valid, 89 Invalid, 1737 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [416 Valid, 1321 Invalid, 0 Unknown, 0 Unchecked, 1.0s Time] [2021-11-23 03:32:04,981 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 69 states. [2021-11-23 03:32:05,013 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 69 to 40. [2021-11-23 03:32:05,013 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 40 states, 39 states have (on average 1.2820512820512822) internal successors, (50), 39 states have internal predecessors, (50), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:32:05,013 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 40 states to 40 states and 50 transitions. [2021-11-23 03:32:05,014 INFO L78 Accepts]: Start accepts. Automaton has 40 states and 50 transitions. Word has length 26 [2021-11-23 03:32:05,014 INFO L84 Accepts]: Finished accepts. word is rejected. [2021-11-23 03:32:05,014 INFO L470 AbstractCegarLoop]: Abstraction has 40 states and 50 transitions. [2021-11-23 03:32:05,014 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 70 states, 70 states have (on average 1.0571428571428572) internal successors, (74), 70 states have internal predecessors, (74), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:32:05,014 INFO L276 IsEmpty]: Start isEmpty. Operand 40 states and 50 transitions. [2021-11-23 03:32:05,015 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 29 [2021-11-23 03:32:05,015 INFO L506 BasicCegarLoop]: Found error trace [2021-11-23 03:32:05,016 INFO L514 BasicCegarLoop]: trace histogram [9, 9, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2021-11-23 03:32:05,036 INFO L540 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (14)] Forceful destruction successful, exit code 0 [2021-11-23 03:32:05,217 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: 14 /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true,SelfDestructingSolverStorable16 [2021-11-23 03:32:05,218 INFO L402 AbstractCegarLoop]: === Iteration 18 === Targeting ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION === [ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2021-11-23 03:32:05,218 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2021-11-23 03:32:05,229 INFO L85 PathProgramCache]: Analyzing trace with hash 14034197, now seen corresponding path program 12 times [2021-11-23 03:32:05,229 INFO L121 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2021-11-23 03:32:05,229 INFO L333 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [970253205] [2021-11-23 03:32:05,229 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:32:05,230 INFO L126 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2021-11-23 03:32:05,244 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:32:06,059 INFO L134 CoverageAnalysis]: Checked inductivity of 90 backedges. 0 proven. 90 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:32:06,059 INFO L139 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2021-11-23 03:32:06,059 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [970253205] [2021-11-23 03:32:06,059 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [970253205] provided 0 perfect and 1 imperfect interpolant sequences [2021-11-23 03:32:06,059 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [68933399] [2021-11-23 03:32:06,059 INFO L93 rtionOrderModulation]: Changing assertion order to TERMS_WITH_SMALL_CONSTANTS_FIRST [2021-11-23 03:32:06,059 INFO L168 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:32:06,060 INFO L189 MonitoredProcess]: No working directory specified, using /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 [2021-11-23 03:32:06,060 INFO L229 MonitoredProcess]: Starting monitored process 15 with /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2021-11-23 03:32:06,061 INFO L327 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (15)] Waiting until timeout for monitored process [2021-11-23 03:32:06,098 INFO L228 tOrderPrioritization]: Assert order TERMS_WITH_SMALL_CONSTANTS_FIRST issued 0 check-sat command(s) [2021-11-23 03:32:06,098 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2021-11-23 03:32:06,100 WARN L261 TraceCheckSpWp]: Trace formula consists of 130 conjuncts, 69 conjunts are in the unsatisfiable core [2021-11-23 03:32:06,102 INFO L286 TraceCheckSpWp]: Computing forward predicates... [2021-11-23 03:32:08,378 INFO L134 CoverageAnalysis]: Checked inductivity of 90 backedges. 0 proven. 90 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:32:08,379 INFO L328 TraceCheckSpWp]: Computing backward predicates... [2021-11-23 03:32:10,364 INFO L134 CoverageAnalysis]: Checked inductivity of 90 backedges. 0 proven. 90 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:32:10,364 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleZ3 [68933399] provided 0 perfect and 2 imperfect interpolant sequences [2021-11-23 03:32:10,365 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [376597494] [2021-11-23 03:32:10,366 INFO L159 IcfgInterpreter]: Started Sifa with 11 locations of interest [2021-11-23 03:32:10,366 INFO L166 IcfgInterpreter]: Building call graph [2021-11-23 03:32:10,367 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2021-11-23 03:32:10,367 INFO L176 IcfgInterpreter]: Starting interpretation [2021-11-23 03:32:10,367 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2021-11-23 03:32:10,534 INFO L180 IcfgInterpreter]: Interpretation finished [2021-11-23 03:32:12,053 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '4641#(and (<= 4 |ULTIMATE.start_correct_version_~i~0#1|) (<= |ULTIMATE.start_correct_version_#res#1| 1) (<= 4 |ULTIMATE.start_student_version_~w#1|) (<= |ULTIMATE.start_main_~is_divisible1~0#1| 1) (<= 4 |ULTIMATE.start_correct_version_~w#1|) (<= 4 |ULTIMATE.start_student_version_#in~w#1|) (<= 0 |ULTIMATE.start_correct_version_~is_divisible~0#1|) (<= |ULTIMATE.start_correct_version_~is_divisible~0#1| 1) (<= ~false~0 0) (<= |#NULL.offset| 0) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| 0) (<= 0 ~false~0) (<= 4 |ULTIMATE.start_correct_version_#in~w#1|) (<= 1 ~true~0) (<= 0 |ULTIMATE.start_correct_version_#res#1|) (or (and (not (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|)) (= |ULTIMATE.start_student_version_~is_divisible~1#1| ~false~0)) (and (<= 1 |ULTIMATE.start_student_version_~is_divisible~1#1|) (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (<= |ULTIMATE.start_student_version_~is_divisible~1#1| 1))) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (= (ite (= |ULTIMATE.start_main_~is_divisible1~0#1| |ULTIMATE.start_main_~is_divisible2~0#1|) 1 0) |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (<= 0 |ULTIMATE.start_main_~is_divisible1~0#1|) (<= ~true~0 1) (= |ULTIMATE.start_student_version_~is_divisible~1#1| |ULTIMATE.start_student_version_#res#1|) (<= 0 |#NULL.offset|) (<= 0 |#StackHeapBarrier|) (= |ULTIMATE.start_main_~is_divisible2~0#1| |ULTIMATE.start_student_version_#res#1|) (<= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (= |#NULL.base| 0))' at error location [2021-11-23 03:32:12,053 WARN L312 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2021-11-23 03:32:12,053 INFO L186 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2021-11-23 03:32:12,054 INFO L199 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [27, 27, 27] total 75 [2021-11-23 03:32:12,054 INFO L115 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [935585363] [2021-11-23 03:32:12,054 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2021-11-23 03:32:12,055 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 75 states [2021-11-23 03:32:12,055 INFO L103 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2021-11-23 03:32:12,055 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 75 interpolants. [2021-11-23 03:32:12,056 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=343, Invalid=6629, Unknown=0, NotChecked=0, Total=6972 [2021-11-23 03:32:12,057 INFO L87 Difference]: Start difference. First operand 40 states and 50 transitions. Second operand has 75 states, 75 states have (on average 1.0533333333333332) internal successors, (79), 75 states have internal predecessors, (79), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:32:30,466 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2021-11-23 03:32:30,467 INFO L93 Difference]: Finished difference Result 115 states and 130 transitions. [2021-11-23 03:32:30,467 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 71 states. [2021-11-23 03:32:30,467 INFO L78 Accepts]: Start accepts. Automaton has has 75 states, 75 states have (on average 1.0533333333333332) internal successors, (79), 75 states have internal predecessors, (79), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 28 [2021-11-23 03:32:30,467 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2021-11-23 03:32:30,468 INFO L225 Difference]: With dead ends: 115 [2021-11-23 03:32:30,468 INFO L226 Difference]: Without dead ends: 92 [2021-11-23 03:32:30,470 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 168 GetRequests, 26 SyntacticMatches, 1 SemanticMatches, 141 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 5776 ImplicationChecksByTransitivity, 22.0s TimeCoverageRelationStatistics Valid=1418, Invalid=18888, Unknown=0, NotChecked=0, Total=20306 [2021-11-23 03:32:30,471 INFO L933 BasicCegarLoop]: 4 mSDtfsCounter, 254 mSDsluCounter, 142 mSDsCounter, 0 mSdLazyCounter, 1786 mSolverCounterSat, 526 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 1.2s Time, 0 mProtectedPredicate, 0 mProtectedAction, 254 SdHoareTripleChecker+Valid, 139 SdHoareTripleChecker+Invalid, 2312 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 526 IncrementalHoareTripleChecker+Valid, 1786 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 1.4s IncrementalHoareTripleChecker+Time [2021-11-23 03:32:30,471 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [254 Valid, 139 Invalid, 2312 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [526 Valid, 1786 Invalid, 0 Unknown, 0 Unchecked, 1.4s Time] [2021-11-23 03:32:30,471 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 92 states. [2021-11-23 03:32:30,518 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 92 to 54. [2021-11-23 03:32:30,518 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 54 states, 53 states have (on average 1.2452830188679245) internal successors, (66), 53 states have internal predecessors, (66), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:32:30,518 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 54 states to 54 states and 66 transitions. [2021-11-23 03:32:30,519 INFO L78 Accepts]: Start accepts. Automaton has 54 states and 66 transitions. Word has length 28 [2021-11-23 03:32:30,519 INFO L84 Accepts]: Finished accepts. word is rejected. [2021-11-23 03:32:30,519 INFO L470 AbstractCegarLoop]: Abstraction has 54 states and 66 transitions. [2021-11-23 03:32:30,519 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 75 states, 75 states have (on average 1.0533333333333332) internal successors, (79), 75 states have internal predecessors, (79), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:32:30,519 INFO L276 IsEmpty]: Start isEmpty. Operand 54 states and 66 transitions. [2021-11-23 03:32:30,520 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 31 [2021-11-23 03:32:30,521 INFO L506 BasicCegarLoop]: Found error trace [2021-11-23 03:32:30,521 INFO L514 BasicCegarLoop]: trace histogram [10, 10, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2021-11-23 03:32:30,543 INFO L552 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (15)] Ended with exit code 0 [2021-11-23 03:32:30,725 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: 15 /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true,SelfDestructingSolverStorable17 [2021-11-23 03:32:30,725 INFO L402 AbstractCegarLoop]: === Iteration 19 === Targeting ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION === [ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2021-11-23 03:32:30,725 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2021-11-23 03:32:30,726 INFO L85 PathProgramCache]: Analyzing trace with hash 236688594, now seen corresponding path program 13 times [2021-11-23 03:32:30,726 INFO L121 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2021-11-23 03:32:30,726 INFO L333 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [854843205] [2021-11-23 03:32:30,726 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:32:30,726 INFO L126 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2021-11-23 03:32:30,736 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:32:31,755 INFO L134 CoverageAnalysis]: Checked inductivity of 110 backedges. 0 proven. 110 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:32:31,755 INFO L139 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2021-11-23 03:32:31,755 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [854843205] [2021-11-23 03:32:31,755 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [854843205] provided 0 perfect and 1 imperfect interpolant sequences [2021-11-23 03:32:31,756 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1062062427] [2021-11-23 03:32:31,756 INFO L93 rtionOrderModulation]: Changing assertion order to NOT_INCREMENTALLY [2021-11-23 03:32:31,756 INFO L168 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:32:31,756 INFO L189 MonitoredProcess]: No working directory specified, using /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 [2021-11-23 03:32:31,761 INFO L229 MonitoredProcess]: Starting monitored process 16 with /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2021-11-23 03:32:31,770 INFO L327 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (16)] Waiting until timeout for monitored process [2021-11-23 03:32:31,804 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:32:31,806 WARN L261 TraceCheckSpWp]: Trace formula consists of 136 conjuncts, 73 conjunts are in the unsatisfiable core [2021-11-23 03:32:31,808 INFO L286 TraceCheckSpWp]: Computing forward predicates... [2021-11-23 03:32:34,491 INFO L134 CoverageAnalysis]: Checked inductivity of 110 backedges. 0 proven. 110 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:32:34,491 INFO L328 TraceCheckSpWp]: Computing backward predicates... [2021-11-23 03:32:36,786 INFO L134 CoverageAnalysis]: Checked inductivity of 110 backedges. 0 proven. 110 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:32:36,787 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1062062427] provided 0 perfect and 2 imperfect interpolant sequences [2021-11-23 03:32:36,787 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [1007553295] [2021-11-23 03:32:36,788 INFO L159 IcfgInterpreter]: Started Sifa with 11 locations of interest [2021-11-23 03:32:36,789 INFO L166 IcfgInterpreter]: Building call graph [2021-11-23 03:32:36,789 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2021-11-23 03:32:36,789 INFO L176 IcfgInterpreter]: Starting interpretation [2021-11-23 03:32:36,789 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2021-11-23 03:32:36,956 INFO L180 IcfgInterpreter]: Interpretation finished [2021-11-23 03:32:38,467 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '5323#(and (<= 4 |ULTIMATE.start_correct_version_~i~0#1|) (<= |ULTIMATE.start_correct_version_#res#1| 1) (<= 4 |ULTIMATE.start_student_version_~w#1|) (<= |ULTIMATE.start_main_~is_divisible1~0#1| 1) (<= 4 |ULTIMATE.start_correct_version_~w#1|) (<= 4 |ULTIMATE.start_student_version_#in~w#1|) (<= 0 |ULTIMATE.start_correct_version_~is_divisible~0#1|) (= ~true~0 1) (<= |ULTIMATE.start_correct_version_~is_divisible~0#1| 1) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| 0) (<= 4 |ULTIMATE.start_correct_version_#in~w#1|) (= ~false~0 0) (<= 0 |ULTIMATE.start_correct_version_#res#1|) (or (and (not (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|)) (= |ULTIMATE.start_student_version_~is_divisible~1#1| ~false~0)) (and (<= 1 |ULTIMATE.start_student_version_~is_divisible~1#1|) (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (<= |ULTIMATE.start_student_version_~is_divisible~1#1| 1))) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (= |#NULL.offset| 0) (= (ite (= |ULTIMATE.start_main_~is_divisible1~0#1| |ULTIMATE.start_main_~is_divisible2~0#1|) 1 0) |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (<= 0 |ULTIMATE.start_main_~is_divisible1~0#1|) (= |ULTIMATE.start_student_version_~is_divisible~1#1| |ULTIMATE.start_student_version_#res#1|) (<= 0 |#StackHeapBarrier|) (= |ULTIMATE.start_main_~is_divisible2~0#1| |ULTIMATE.start_student_version_#res#1|) (<= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (= |#NULL.base| 0))' at error location [2021-11-23 03:32:38,467 WARN L312 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2021-11-23 03:32:38,467 INFO L186 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2021-11-23 03:32:38,467 INFO L199 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [29, 29, 29] total 81 [2021-11-23 03:32:38,467 INFO L115 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1437982349] [2021-11-23 03:32:38,468 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2021-11-23 03:32:38,468 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 81 states [2021-11-23 03:32:38,468 INFO L103 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2021-11-23 03:32:38,469 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 81 interpolants. [2021-11-23 03:32:38,469 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=370, Invalid=7640, Unknown=0, NotChecked=0, Total=8010 [2021-11-23 03:32:38,470 INFO L87 Difference]: Start difference. First operand 54 states and 66 transitions. Second operand has 81 states, 81 states have (on average 1.0493827160493827) internal successors, (85), 81 states have internal predecessors, (85), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:32:57,688 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2021-11-23 03:32:57,688 INFO L93 Difference]: Finished difference Result 132 states and 151 transitions. [2021-11-23 03:32:57,688 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 76 states. [2021-11-23 03:32:57,689 INFO L78 Accepts]: Start accepts. Automaton has has 81 states, 81 states have (on average 1.0493827160493827) internal successors, (85), 81 states have internal predecessors, (85), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 30 [2021-11-23 03:32:57,689 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2021-11-23 03:32:57,689 INFO L225 Difference]: With dead ends: 132 [2021-11-23 03:32:57,689 INFO L226 Difference]: Without dead ends: 108 [2021-11-23 03:32:57,690 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 180 GetRequests, 28 SyntacticMatches, 1 SemanticMatches, 151 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 6663 ImplicationChecksByTransitivity, 23.3s TimeCoverageRelationStatistics Valid=1550, Invalid=21706, Unknown=0, NotChecked=0, Total=23256 [2021-11-23 03:32:57,691 INFO L933 BasicCegarLoop]: 4 mSDtfsCounter, 272 mSDsluCounter, 155 mSDsCounter, 0 mSdLazyCounter, 1938 mSolverCounterSat, 650 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 1.4s Time, 0 mProtectedPredicate, 0 mProtectedAction, 272 SdHoareTripleChecker+Valid, 153 SdHoareTripleChecker+Invalid, 2588 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 650 IncrementalHoareTripleChecker+Valid, 1938 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 1.6s IncrementalHoareTripleChecker+Time [2021-11-23 03:32:57,691 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [272 Valid, 153 Invalid, 2588 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [650 Valid, 1938 Invalid, 0 Unknown, 0 Unchecked, 1.6s Time] [2021-11-23 03:32:57,692 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 108 states. [2021-11-23 03:32:57,767 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 108 to 69. [2021-11-23 03:32:57,767 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 69 states, 68 states have (on average 1.2352941176470589) internal successors, (84), 68 states have internal predecessors, (84), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:32:57,768 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 69 states to 69 states and 84 transitions. [2021-11-23 03:32:57,768 INFO L78 Accepts]: Start accepts. Automaton has 69 states and 84 transitions. Word has length 30 [2021-11-23 03:32:57,768 INFO L84 Accepts]: Finished accepts. word is rejected. [2021-11-23 03:32:57,768 INFO L470 AbstractCegarLoop]: Abstraction has 69 states and 84 transitions. [2021-11-23 03:32:57,769 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 81 states, 81 states have (on average 1.0493827160493827) internal successors, (85), 81 states have internal predecessors, (85), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:32:57,769 INFO L276 IsEmpty]: Start isEmpty. Operand 69 states and 84 transitions. [2021-11-23 03:32:57,770 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 33 [2021-11-23 03:32:57,770 INFO L506 BasicCegarLoop]: Found error trace [2021-11-23 03:32:57,770 INFO L514 BasicCegarLoop]: trace histogram [11, 11, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2021-11-23 03:32:57,796 INFO L540 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (16)] Forceful destruction successful, exit code 0 [2021-11-23 03:32:57,972 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable18,16 /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:32:57,972 INFO L402 AbstractCegarLoop]: === Iteration 20 === Targeting ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION === [ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2021-11-23 03:32:57,973 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2021-11-23 03:32:57,973 INFO L85 PathProgramCache]: Analyzing trace with hash -1993851979, now seen corresponding path program 14 times [2021-11-23 03:32:57,973 INFO L121 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2021-11-23 03:32:57,973 INFO L333 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [7365242] [2021-11-23 03:32:57,973 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:32:57,973 INFO L126 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2021-11-23 03:32:57,987 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:32:58,932 INFO L134 CoverageAnalysis]: Checked inductivity of 132 backedges. 0 proven. 132 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:32:58,932 INFO L139 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2021-11-23 03:32:58,932 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [7365242] [2021-11-23 03:32:58,933 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [7365242] provided 0 perfect and 1 imperfect interpolant sequences [2021-11-23 03:32:58,933 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [507689972] [2021-11-23 03:32:58,933 INFO L93 rtionOrderModulation]: Changing assertion order to OUTSIDE_LOOP_FIRST2 [2021-11-23 03:32:58,933 INFO L168 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:32:58,933 INFO L189 MonitoredProcess]: No working directory specified, using /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 [2021-11-23 03:32:58,934 INFO L229 MonitoredProcess]: Starting monitored process 17 with /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2021-11-23 03:32:58,935 INFO L327 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (17)] Waiting until timeout for monitored process [2021-11-23 03:32:58,972 INFO L228 tOrderPrioritization]: Assert order OUTSIDE_LOOP_FIRST2 issued 7 check-sat command(s) [2021-11-23 03:32:58,972 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2021-11-23 03:32:58,974 WARN L261 TraceCheckSpWp]: Trace formula consists of 142 conjuncts, 79 conjunts are in the unsatisfiable core [2021-11-23 03:32:58,975 INFO L286 TraceCheckSpWp]: Computing forward predicates... [2021-11-23 03:33:02,069 INFO L134 CoverageAnalysis]: Checked inductivity of 132 backedges. 0 proven. 132 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:33:02,069 INFO L328 TraceCheckSpWp]: Computing backward predicates... [2021-11-23 03:33:04,972 INFO L134 CoverageAnalysis]: Checked inductivity of 132 backedges. 0 proven. 132 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:33:04,973 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleZ3 [507689972] provided 0 perfect and 2 imperfect interpolant sequences [2021-11-23 03:33:04,973 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [1896116588] [2021-11-23 03:33:04,976 INFO L159 IcfgInterpreter]: Started Sifa with 11 locations of interest [2021-11-23 03:33:04,976 INFO L166 IcfgInterpreter]: Building call graph [2021-11-23 03:33:04,977 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2021-11-23 03:33:04,977 INFO L176 IcfgInterpreter]: Starting interpretation [2021-11-23 03:33:04,977 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2021-11-23 03:33:05,129 INFO L180 IcfgInterpreter]: Interpretation finished [2021-11-23 03:33:06,792 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '6094#(and (<= 4 |ULTIMATE.start_correct_version_~i~0#1|) (<= |ULTIMATE.start_correct_version_#res#1| 1) (<= 4 |ULTIMATE.start_student_version_~w#1|) (<= |ULTIMATE.start_main_~is_divisible1~0#1| 1) (<= 4 |ULTIMATE.start_correct_version_~w#1|) (<= 4 |ULTIMATE.start_student_version_#in~w#1|) (<= 0 |ULTIMATE.start_correct_version_~is_divisible~0#1|) (<= |ULTIMATE.start_correct_version_~is_divisible~0#1| 1) (<= ~false~0 0) (<= |#NULL.offset| 0) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| 0) (<= 0 ~false~0) (<= 4 |ULTIMATE.start_correct_version_#in~w#1|) (<= 1 ~true~0) (<= 0 |ULTIMATE.start_correct_version_#res#1|) (or (and (not (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|)) (= |ULTIMATE.start_student_version_~is_divisible~1#1| ~false~0)) (and (<= 1 |ULTIMATE.start_student_version_~is_divisible~1#1|) (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (<= |ULTIMATE.start_student_version_~is_divisible~1#1| 1))) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (= (ite (= |ULTIMATE.start_main_~is_divisible1~0#1| |ULTIMATE.start_main_~is_divisible2~0#1|) 1 0) |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (<= 0 |ULTIMATE.start_main_~is_divisible1~0#1|) (<= ~true~0 1) (= |ULTIMATE.start_student_version_~is_divisible~1#1| |ULTIMATE.start_student_version_#res#1|) (<= 0 |#NULL.offset|) (<= 0 |#StackHeapBarrier|) (= |ULTIMATE.start_main_~is_divisible2~0#1| |ULTIMATE.start_student_version_#res#1|) (<= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (= |#NULL.base| 0))' at error location [2021-11-23 03:33:06,792 WARN L312 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2021-11-23 03:33:06,793 INFO L186 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2021-11-23 03:33:06,793 INFO L199 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [31, 31, 31] total 88 [2021-11-23 03:33:06,793 INFO L115 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1275027755] [2021-11-23 03:33:06,793 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2021-11-23 03:33:06,794 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 88 states [2021-11-23 03:33:06,794 INFO L103 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2021-11-23 03:33:06,794 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 88 interpolants. [2021-11-23 03:33:06,795 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=400, Invalid=8912, Unknown=0, NotChecked=0, Total=9312 [2021-11-23 03:33:06,796 INFO L87 Difference]: Start difference. First operand 69 states and 84 transitions. Second operand has 88 states, 88 states have (on average 1.0454545454545454) internal successors, (92), 88 states have internal predecessors, (92), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:33:22,882 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2021-11-23 03:33:22,883 INFO L93 Difference]: Finished difference Result 150 states and 174 transitions. [2021-11-23 03:33:22,884 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 81 states. [2021-11-23 03:33:22,884 INFO L78 Accepts]: Start accepts. Automaton has has 88 states, 88 states have (on average 1.0454545454545454) internal successors, (92), 88 states have internal predecessors, (92), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 32 [2021-11-23 03:33:22,884 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2021-11-23 03:33:22,885 INFO L225 Difference]: With dead ends: 150 [2021-11-23 03:33:22,885 INFO L226 Difference]: Without dead ends: 125 [2021-11-23 03:33:22,887 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 192 GetRequests, 29 SyntacticMatches, 1 SemanticMatches, 162 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 7751 ImplicationChecksByTransitivity, 20.7s TimeCoverageRelationStatistics Valid=1691, Invalid=25041, Unknown=0, NotChecked=0, Total=26732 [2021-11-23 03:33:22,887 INFO L933 BasicCegarLoop]: 4 mSDtfsCounter, 276 mSDsluCounter, 157 mSDsCounter, 0 mSdLazyCounter, 2348 mSolverCounterSat, 701 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 1.6s Time, 0 mProtectedPredicate, 0 mProtectedAction, 276 SdHoareTripleChecker+Valid, 157 SdHoareTripleChecker+Invalid, 3049 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 701 IncrementalHoareTripleChecker+Valid, 2348 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 1.9s IncrementalHoareTripleChecker+Time [2021-11-23 03:33:22,888 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [276 Valid, 157 Invalid, 3049 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [701 Valid, 2348 Invalid, 0 Unknown, 0 Unchecked, 1.9s Time] [2021-11-23 03:33:22,888 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 125 states. [2021-11-23 03:33:22,995 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 125 to 85. [2021-11-23 03:33:22,996 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 85 states, 84 states have (on average 1.2380952380952381) internal successors, (104), 84 states have internal predecessors, (104), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:33:22,996 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 85 states to 85 states and 104 transitions. [2021-11-23 03:33:22,997 INFO L78 Accepts]: Start accepts. Automaton has 85 states and 104 transitions. Word has length 32 [2021-11-23 03:33:22,997 INFO L84 Accepts]: Finished accepts. word is rejected. [2021-11-23 03:33:22,997 INFO L470 AbstractCegarLoop]: Abstraction has 85 states and 104 transitions. [2021-11-23 03:33:22,997 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 88 states, 88 states have (on average 1.0454545454545454) internal successors, (92), 88 states have internal predecessors, (92), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:33:22,998 INFO L276 IsEmpty]: Start isEmpty. Operand 85 states and 104 transitions. [2021-11-23 03:33:22,998 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 35 [2021-11-23 03:33:22,998 INFO L506 BasicCegarLoop]: Found error trace [2021-11-23 03:33:22,999 INFO L514 BasicCegarLoop]: trace histogram [12, 12, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2021-11-23 03:33:23,019 INFO L552 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (17)] Ended with exit code 0 [2021-11-23 03:33:23,201 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable19,17 /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:33:23,202 INFO L402 AbstractCegarLoop]: === Iteration 21 === Targeting ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION === [ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2021-11-23 03:33:23,202 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2021-11-23 03:33:23,202 INFO L85 PathProgramCache]: Analyzing trace with hash -154611662, now seen corresponding path program 15 times [2021-11-23 03:33:23,202 INFO L121 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2021-11-23 03:33:23,202 INFO L333 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [658010330] [2021-11-23 03:33:23,202 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:33:23,203 INFO L126 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2021-11-23 03:33:23,214 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:33:24,258 INFO L134 CoverageAnalysis]: Checked inductivity of 156 backedges. 0 proven. 156 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:33:24,258 INFO L139 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2021-11-23 03:33:24,259 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [658010330] [2021-11-23 03:33:24,259 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [658010330] provided 0 perfect and 1 imperfect interpolant sequences [2021-11-23 03:33:24,259 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [496331201] [2021-11-23 03:33:24,259 INFO L93 rtionOrderModulation]: Changing assertion order to TERMS_WITH_SMALL_CONSTANTS_FIRST [2021-11-23 03:33:24,259 INFO L168 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:33:24,259 INFO L189 MonitoredProcess]: No working directory specified, using /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 [2021-11-23 03:33:24,260 INFO L229 MonitoredProcess]: Starting monitored process 18 with /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2021-11-23 03:33:24,261 INFO L327 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (18)] Waiting until timeout for monitored process [2021-11-23 03:33:24,295 INFO L228 tOrderPrioritization]: Assert order TERMS_WITH_SMALL_CONSTANTS_FIRST issued 0 check-sat command(s) [2021-11-23 03:33:24,296 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2021-11-23 03:33:24,297 WARN L261 TraceCheckSpWp]: Trace formula consists of 148 conjuncts, 81 conjunts are in the unsatisfiable core [2021-11-23 03:33:24,299 INFO L286 TraceCheckSpWp]: Computing forward predicates... [2021-11-23 03:33:28,092 INFO L134 CoverageAnalysis]: Checked inductivity of 156 backedges. 0 proven. 156 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:33:28,092 INFO L328 TraceCheckSpWp]: Computing backward predicates... [2021-11-23 03:33:30,997 INFO L134 CoverageAnalysis]: Checked inductivity of 156 backedges. 0 proven. 156 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:33:30,997 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleZ3 [496331201] provided 0 perfect and 2 imperfect interpolant sequences [2021-11-23 03:33:30,997 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [629386202] [2021-11-23 03:33:30,998 INFO L159 IcfgInterpreter]: Started Sifa with 11 locations of interest [2021-11-23 03:33:30,999 INFO L166 IcfgInterpreter]: Building call graph [2021-11-23 03:33:30,999 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2021-11-23 03:33:30,999 INFO L176 IcfgInterpreter]: Starting interpretation [2021-11-23 03:33:30,999 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2021-11-23 03:33:31,165 INFO L180 IcfgInterpreter]: Interpretation finished [2021-11-23 03:33:32,761 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '6956#(and (<= 4 |ULTIMATE.start_correct_version_~i~0#1|) (<= |ULTIMATE.start_correct_version_#res#1| 1) (<= 4 |ULTIMATE.start_student_version_~w#1|) (<= |ULTIMATE.start_main_~is_divisible1~0#1| 1) (<= 4 |ULTIMATE.start_correct_version_~w#1|) (<= 4 |ULTIMATE.start_student_version_#in~w#1|) (<= 0 |ULTIMATE.start_correct_version_~is_divisible~0#1|) (= ~true~0 1) (<= |ULTIMATE.start_correct_version_~is_divisible~0#1| 1) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| 0) (<= 4 |ULTIMATE.start_correct_version_#in~w#1|) (= ~false~0 0) (<= 0 |ULTIMATE.start_correct_version_#res#1|) (or (and (not (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|)) (= |ULTIMATE.start_student_version_~is_divisible~1#1| ~false~0)) (and (<= 1 |ULTIMATE.start_student_version_~is_divisible~1#1|) (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (<= |ULTIMATE.start_student_version_~is_divisible~1#1| 1))) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (= |#NULL.offset| 0) (= (ite (= |ULTIMATE.start_main_~is_divisible1~0#1| |ULTIMATE.start_main_~is_divisible2~0#1|) 1 0) |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (<= 0 |ULTIMATE.start_main_~is_divisible1~0#1|) (= |ULTIMATE.start_student_version_~is_divisible~1#1| |ULTIMATE.start_student_version_#res#1|) (<= 0 |#StackHeapBarrier|) (= |ULTIMATE.start_main_~is_divisible2~0#1| |ULTIMATE.start_student_version_#res#1|) (<= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (= |#NULL.base| 0))' at error location [2021-11-23 03:33:32,761 WARN L312 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2021-11-23 03:33:32,761 INFO L186 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2021-11-23 03:33:32,761 INFO L199 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [33, 33, 33] total 93 [2021-11-23 03:33:32,761 INFO L115 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [2083374707] [2021-11-23 03:33:32,761 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2021-11-23 03:33:32,762 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 93 states [2021-11-23 03:33:32,762 INFO L103 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2021-11-23 03:33:32,762 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 93 interpolants. [2021-11-23 03:33:32,763 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=424, Invalid=9878, Unknown=0, NotChecked=0, Total=10302 [2021-11-23 03:33:32,763 INFO L87 Difference]: Start difference. First operand 85 states and 104 transitions. Second operand has 93 states, 93 states have (on average 1.043010752688172) internal successors, (97), 93 states have internal predecessors, (97), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:34:01,433 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2021-11-23 03:34:01,433 INFO L93 Difference]: Finished difference Result 169 states and 199 transitions. [2021-11-23 03:34:01,433 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 86 states. [2021-11-23 03:34:01,434 INFO L78 Accepts]: Start accepts. Automaton has has 93 states, 93 states have (on average 1.043010752688172) internal successors, (97), 93 states have internal predecessors, (97), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 34 [2021-11-23 03:34:01,434 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2021-11-23 03:34:01,435 INFO L225 Difference]: With dead ends: 169 [2021-11-23 03:34:01,435 INFO L226 Difference]: Without dead ends: 143 [2021-11-23 03:34:01,437 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 204 GetRequests, 32 SyntacticMatches, 1 SemanticMatches, 171 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 8623 ImplicationChecksByTransitivity, 33.4s TimeCoverageRelationStatistics Valid=1826, Invalid=27930, Unknown=0, NotChecked=0, Total=29756 [2021-11-23 03:34:01,438 INFO L933 BasicCegarLoop]: 4 mSDtfsCounter, 320 mSDsluCounter, 167 mSDsCounter, 0 mSdLazyCounter, 2540 mSolverCounterSat, 921 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 2.0s Time, 0 mProtectedPredicate, 0 mProtectedAction, 320 SdHoareTripleChecker+Valid, 165 SdHoareTripleChecker+Invalid, 3461 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 921 IncrementalHoareTripleChecker+Valid, 2540 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 2.3s IncrementalHoareTripleChecker+Time [2021-11-23 03:34:01,438 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [320 Valid, 165 Invalid, 3461 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [921 Valid, 2540 Invalid, 0 Unknown, 0 Unchecked, 2.3s Time] [2021-11-23 03:34:01,439 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 143 states. [2021-11-23 03:34:01,601 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 143 to 102. [2021-11-23 03:34:01,601 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 102 states, 101 states have (on average 1.2475247524752475) internal successors, (126), 101 states have internal predecessors, (126), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:34:01,601 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 102 states to 102 states and 126 transitions. [2021-11-23 03:34:01,602 INFO L78 Accepts]: Start accepts. Automaton has 102 states and 126 transitions. Word has length 34 [2021-11-23 03:34:01,602 INFO L84 Accepts]: Finished accepts. word is rejected. [2021-11-23 03:34:01,602 INFO L470 AbstractCegarLoop]: Abstraction has 102 states and 126 transitions. [2021-11-23 03:34:01,602 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 93 states, 93 states have (on average 1.043010752688172) internal successors, (97), 93 states have internal predecessors, (97), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:34:01,602 INFO L276 IsEmpty]: Start isEmpty. Operand 102 states and 126 transitions. [2021-11-23 03:34:01,603 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 37 [2021-11-23 03:34:01,603 INFO L506 BasicCegarLoop]: Found error trace [2021-11-23 03:34:01,603 INFO L514 BasicCegarLoop]: trace histogram [13, 13, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2021-11-23 03:34:01,624 INFO L540 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (18)] Forceful destruction successful, exit code 0 [2021-11-23 03:34:01,805 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable20,18 /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:34:01,806 INFO L402 AbstractCegarLoop]: === Iteration 22 === Targeting ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION === [ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2021-11-23 03:34:01,806 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2021-11-23 03:34:01,806 INFO L85 PathProgramCache]: Analyzing trace with hash 1605855829, now seen corresponding path program 16 times [2021-11-23 03:34:01,806 INFO L121 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2021-11-23 03:34:01,806 INFO L333 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [378241056] [2021-11-23 03:34:01,806 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:34:01,806 INFO L126 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2021-11-23 03:34:01,819 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:34:03,017 INFO L134 CoverageAnalysis]: Checked inductivity of 182 backedges. 0 proven. 182 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:34:03,017 INFO L139 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2021-11-23 03:34:03,017 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [378241056] [2021-11-23 03:34:03,017 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [378241056] provided 0 perfect and 1 imperfect interpolant sequences [2021-11-23 03:34:03,017 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [660920192] [2021-11-23 03:34:03,017 INFO L93 rtionOrderModulation]: Changing assertion order to NOT_INCREMENTALLY [2021-11-23 03:34:03,017 INFO L168 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:34:03,017 INFO L189 MonitoredProcess]: No working directory specified, using /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 [2021-11-23 03:34:03,020 INFO L229 MonitoredProcess]: Starting monitored process 19 with /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2021-11-23 03:34:03,021 INFO L327 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (19)] Waiting until timeout for monitored process [2021-11-23 03:34:03,055 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:34:03,056 WARN L261 TraceCheckSpWp]: Trace formula consists of 154 conjuncts, 85 conjunts are in the unsatisfiable core [2021-11-23 03:34:03,058 INFO L286 TraceCheckSpWp]: Computing forward predicates... [2021-11-23 03:34:06,530 INFO L134 CoverageAnalysis]: Checked inductivity of 182 backedges. 0 proven. 182 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:34:06,530 INFO L328 TraceCheckSpWp]: Computing backward predicates... [2021-11-23 03:34:09,773 INFO L134 CoverageAnalysis]: Checked inductivity of 182 backedges. 0 proven. 182 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:34:09,774 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleZ3 [660920192] provided 0 perfect and 2 imperfect interpolant sequences [2021-11-23 03:34:09,774 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [1063191787] [2021-11-23 03:34:09,775 INFO L159 IcfgInterpreter]: Started Sifa with 11 locations of interest [2021-11-23 03:34:09,776 INFO L166 IcfgInterpreter]: Building call graph [2021-11-23 03:34:09,776 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2021-11-23 03:34:09,776 INFO L176 IcfgInterpreter]: Starting interpretation [2021-11-23 03:34:09,776 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2021-11-23 03:34:09,965 INFO L180 IcfgInterpreter]: Interpretation finished [2021-11-23 03:34:11,795 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '7914#(and (<= 4 |ULTIMATE.start_correct_version_~i~0#1|) (<= |ULTIMATE.start_correct_version_#res#1| 1) (<= 4 |ULTIMATE.start_student_version_~w#1|) (<= |ULTIMATE.start_main_~is_divisible1~0#1| 1) (<= 4 |ULTIMATE.start_correct_version_~w#1|) (<= 4 |ULTIMATE.start_student_version_#in~w#1|) (<= 0 |ULTIMATE.start_correct_version_~is_divisible~0#1|) (<= |ULTIMATE.start_correct_version_~is_divisible~0#1| 1) (<= ~false~0 0) (<= |#NULL.offset| 0) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| 0) (<= 0 ~false~0) (<= 4 |ULTIMATE.start_correct_version_#in~w#1|) (<= 1 ~true~0) (<= 0 |ULTIMATE.start_correct_version_#res#1|) (or (and (not (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|)) (= |ULTIMATE.start_student_version_~is_divisible~1#1| ~false~0)) (and (<= 1 |ULTIMATE.start_student_version_~is_divisible~1#1|) (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (<= |ULTIMATE.start_student_version_~is_divisible~1#1| 1))) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (= (ite (= |ULTIMATE.start_main_~is_divisible1~0#1| |ULTIMATE.start_main_~is_divisible2~0#1|) 1 0) |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (<= 0 |ULTIMATE.start_main_~is_divisible1~0#1|) (<= ~true~0 1) (= |ULTIMATE.start_student_version_~is_divisible~1#1| |ULTIMATE.start_student_version_#res#1|) (<= 0 |#NULL.offset|) (<= 0 |#StackHeapBarrier|) (= |ULTIMATE.start_main_~is_divisible2~0#1| |ULTIMATE.start_student_version_#res#1|) (<= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (= |#NULL.base| 0))' at error location [2021-11-23 03:34:11,796 WARN L312 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2021-11-23 03:34:11,796 INFO L186 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2021-11-23 03:34:11,796 INFO L199 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [35, 35, 35] total 99 [2021-11-23 03:34:11,796 INFO L115 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [995414183] [2021-11-23 03:34:11,796 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2021-11-23 03:34:11,796 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 99 states [2021-11-23 03:34:11,796 INFO L103 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2021-11-23 03:34:11,797 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 99 interpolants. [2021-11-23 03:34:11,797 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=451, Invalid=11105, Unknown=0, NotChecked=0, Total=11556 [2021-11-23 03:34:11,798 INFO L87 Difference]: Start difference. First operand 102 states and 126 transitions. Second operand has 99 states, 99 states have (on average 1.0404040404040404) internal successors, (103), 99 states have internal predecessors, (103), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:34:42,589 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2021-11-23 03:34:42,590 INFO L93 Difference]: Finished difference Result 189 states and 226 transitions. [2021-11-23 03:34:42,591 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 91 states. [2021-11-23 03:34:42,591 INFO L78 Accepts]: Start accepts. Automaton has has 99 states, 99 states have (on average 1.0404040404040404) internal successors, (103), 99 states have internal predecessors, (103), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 36 [2021-11-23 03:34:42,591 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2021-11-23 03:34:42,592 INFO L225 Difference]: With dead ends: 189 [2021-11-23 03:34:42,592 INFO L226 Difference]: Without dead ends: 162 [2021-11-23 03:34:42,595 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 216 GetRequests, 34 SyntacticMatches, 1 SemanticMatches, 181 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 9694 ImplicationChecksByTransitivity, 35.8s TimeCoverageRelationStatistics Valid=1970, Invalid=31336, Unknown=0, NotChecked=0, Total=33306 [2021-11-23 03:34:42,595 INFO L933 BasicCegarLoop]: 2 mSDtfsCounter, 366 mSDsluCounter, 152 mSDsCounter, 0 mSdLazyCounter, 3146 mSolverCounterSat, 1007 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 2.2s Time, 0 mProtectedPredicate, 0 mProtectedAction, 366 SdHoareTripleChecker+Valid, 148 SdHoareTripleChecker+Invalid, 4153 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 1007 IncrementalHoareTripleChecker+Valid, 3146 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 2.5s IncrementalHoareTripleChecker+Time [2021-11-23 03:34:42,596 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [366 Valid, 148 Invalid, 4153 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [1007 Valid, 3146 Invalid, 0 Unknown, 0 Unchecked, 2.5s Time] [2021-11-23 03:34:42,597 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 162 states. [2021-11-23 03:34:42,770 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 162 to 120. [2021-11-23 03:34:42,770 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 120 states, 119 states have (on average 1.2605042016806722) internal successors, (150), 119 states have internal predecessors, (150), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:34:42,771 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 120 states to 120 states and 150 transitions. [2021-11-23 03:34:42,771 INFO L78 Accepts]: Start accepts. Automaton has 120 states and 150 transitions. Word has length 36 [2021-11-23 03:34:42,772 INFO L84 Accepts]: Finished accepts. word is rejected. [2021-11-23 03:34:42,772 INFO L470 AbstractCegarLoop]: Abstraction has 120 states and 150 transitions. [2021-11-23 03:34:42,772 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 99 states, 99 states have (on average 1.0404040404040404) internal successors, (103), 99 states have internal predecessors, (103), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:34:42,772 INFO L276 IsEmpty]: Start isEmpty. Operand 120 states and 150 transitions. [2021-11-23 03:34:42,773 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 37 [2021-11-23 03:34:42,773 INFO L506 BasicCegarLoop]: Found error trace [2021-11-23 03:34:42,773 INFO L514 BasicCegarLoop]: trace histogram [18, 8, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2021-11-23 03:34:42,804 INFO L540 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (19)] Forceful destruction successful, exit code 0 [2021-11-23 03:34:42,989 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable21,19 /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:34:42,990 INFO L402 AbstractCegarLoop]: === Iteration 23 === Targeting ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION === [ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2021-11-23 03:34:42,990 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2021-11-23 03:34:42,990 INFO L85 PathProgramCache]: Analyzing trace with hash -364431630, now seen corresponding path program 17 times [2021-11-23 03:34:42,990 INFO L121 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2021-11-23 03:34:42,990 INFO L333 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [406165115] [2021-11-23 03:34:42,990 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:34:42,990 INFO L126 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2021-11-23 03:34:42,999 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:34:43,905 INFO L134 CoverageAnalysis]: Checked inductivity of 207 backedges. 136 proven. 71 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:34:43,905 INFO L139 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2021-11-23 03:34:43,905 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [406165115] [2021-11-23 03:34:43,905 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [406165115] provided 0 perfect and 1 imperfect interpolant sequences [2021-11-23 03:34:43,905 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1606897512] [2021-11-23 03:34:43,905 INFO L93 rtionOrderModulation]: Changing assertion order to OUTSIDE_LOOP_FIRST2 [2021-11-23 03:34:43,905 INFO L168 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:34:43,906 INFO L189 MonitoredProcess]: No working directory specified, using /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 [2021-11-23 03:34:43,907 INFO L229 MonitoredProcess]: Starting monitored process 20 with /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2021-11-23 03:34:43,911 INFO L327 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (20)] Waiting until timeout for monitored process [2021-11-23 03:34:43,952 INFO L228 tOrderPrioritization]: Assert order OUTSIDE_LOOP_FIRST2 issued 10 check-sat command(s) [2021-11-23 03:34:43,953 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2021-11-23 03:34:43,954 INFO L263 TraceCheckSpWp]: Trace formula consists of 154 conjuncts, 24 conjunts are in the unsatisfiable core [2021-11-23 03:34:43,955 INFO L286 TraceCheckSpWp]: Computing forward predicates... [2021-11-23 03:34:44,738 INFO L134 CoverageAnalysis]: Checked inductivity of 207 backedges. 36 proven. 126 refuted. 0 times theorem prover too weak. 45 trivial. 0 not checked. [2021-11-23 03:34:44,738 INFO L328 TraceCheckSpWp]: Computing backward predicates... [2021-11-23 03:34:45,498 INFO L134 CoverageAnalysis]: Checked inductivity of 207 backedges. 126 proven. 36 refuted. 0 times theorem prover too weak. 45 trivial. 0 not checked. [2021-11-23 03:34:45,498 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1606897512] provided 0 perfect and 2 imperfect interpolant sequences [2021-11-23 03:34:45,498 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [1479255240] [2021-11-23 03:34:45,499 INFO L159 IcfgInterpreter]: Started Sifa with 11 locations of interest [2021-11-23 03:34:45,499 INFO L166 IcfgInterpreter]: Building call graph [2021-11-23 03:34:45,500 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2021-11-23 03:34:45,500 INFO L176 IcfgInterpreter]: Starting interpretation [2021-11-23 03:34:45,500 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2021-11-23 03:34:45,650 INFO L180 IcfgInterpreter]: Interpretation finished [2021-11-23 03:34:46,581 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '8928#(and (<= 4 |ULTIMATE.start_correct_version_~i~0#1|) (<= |ULTIMATE.start_correct_version_#res#1| 1) (<= 4 |ULTIMATE.start_student_version_~w#1|) (<= |ULTIMATE.start_main_~is_divisible1~0#1| 1) (<= 4 |ULTIMATE.start_correct_version_~w#1|) (<= 4 |ULTIMATE.start_student_version_#in~w#1|) (<= 0 |ULTIMATE.start_correct_version_~is_divisible~0#1|) (= ~true~0 1) (<= |ULTIMATE.start_correct_version_~is_divisible~0#1| 1) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| 0) (<= 4 |ULTIMATE.start_correct_version_#in~w#1|) (= ~false~0 0) (<= 0 |ULTIMATE.start_correct_version_#res#1|) (or (and (not (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|)) (= |ULTIMATE.start_student_version_~is_divisible~1#1| ~false~0)) (and (<= 1 |ULTIMATE.start_student_version_~is_divisible~1#1|) (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (<= |ULTIMATE.start_student_version_~is_divisible~1#1| 1))) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (= |#NULL.offset| 0) (= (ite (= |ULTIMATE.start_main_~is_divisible1~0#1| |ULTIMATE.start_main_~is_divisible2~0#1|) 1 0) |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (<= 0 |ULTIMATE.start_main_~is_divisible1~0#1|) (= |ULTIMATE.start_student_version_~is_divisible~1#1| |ULTIMATE.start_student_version_#res#1|) (<= 0 |#StackHeapBarrier|) (= |ULTIMATE.start_main_~is_divisible2~0#1| |ULTIMATE.start_student_version_#res#1|) (<= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (= |#NULL.base| 0))' at error location [2021-11-23 03:34:46,581 WARN L312 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2021-11-23 03:34:46,581 INFO L186 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2021-11-23 03:34:46,582 INFO L199 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [33, 23, 23] total 73 [2021-11-23 03:34:46,582 INFO L115 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [2060764819] [2021-11-23 03:34:46,582 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2021-11-23 03:34:46,582 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 73 states [2021-11-23 03:34:46,582 INFO L103 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2021-11-23 03:34:46,583 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 73 interpolants. [2021-11-23 03:34:46,584 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=1054, Invalid=5588, Unknown=0, NotChecked=0, Total=6642 [2021-11-23 03:34:46,584 INFO L87 Difference]: Start difference. First operand 120 states and 150 transitions. Second operand has 73 states, 73 states have (on average 1.1095890410958904) internal successors, (81), 73 states have internal predecessors, (81), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:34:51,157 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2021-11-23 03:34:51,157 INFO L93 Difference]: Finished difference Result 215 states and 254 transitions. [2021-11-23 03:34:51,157 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 81 states. [2021-11-23 03:34:51,157 INFO L78 Accepts]: Start accepts. Automaton has has 73 states, 73 states have (on average 1.1095890410958904) internal successors, (81), 73 states have internal predecessors, (81), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 36 [2021-11-23 03:34:51,157 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2021-11-23 03:34:51,160 INFO L225 Difference]: With dead ends: 215 [2021-11-23 03:34:51,160 INFO L226 Difference]: Without dead ends: 211 [2021-11-23 03:34:51,161 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 208 GetRequests, 57 SyntacticMatches, 2 SemanticMatches, 149 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 6022 ImplicationChecksByTransitivity, 6.5s TimeCoverageRelationStatistics Valid=5953, Invalid=16697, Unknown=0, NotChecked=0, Total=22650 [2021-11-23 03:34:51,162 INFO L933 BasicCegarLoop]: 11 mSDtfsCounter, 68 mSDsluCounter, 101 mSDsCounter, 0 mSdLazyCounter, 522 mSolverCounterSat, 126 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.3s Time, 0 mProtectedPredicate, 0 mProtectedAction, 68 SdHoareTripleChecker+Valid, 77 SdHoareTripleChecker+Invalid, 648 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 126 IncrementalHoareTripleChecker+Valid, 522 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.3s IncrementalHoareTripleChecker+Time [2021-11-23 03:34:51,162 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [68 Valid, 77 Invalid, 648 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [126 Valid, 522 Invalid, 0 Unknown, 0 Unchecked, 0.3s Time] [2021-11-23 03:34:51,163 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 211 states. [2021-11-23 03:34:51,248 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 211 to 49. [2021-11-23 03:34:51,249 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 49 states, 48 states have (on average 1.125) internal successors, (54), 48 states have internal predecessors, (54), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:34:51,249 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 49 states to 49 states and 54 transitions. [2021-11-23 03:34:51,249 INFO L78 Accepts]: Start accepts. Automaton has 49 states and 54 transitions. Word has length 36 [2021-11-23 03:34:51,249 INFO L84 Accepts]: Finished accepts. word is rejected. [2021-11-23 03:34:51,249 INFO L470 AbstractCegarLoop]: Abstraction has 49 states and 54 transitions. [2021-11-23 03:34:51,250 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 73 states, 73 states have (on average 1.1095890410958904) internal successors, (81), 73 states have internal predecessors, (81), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:34:51,250 INFO L276 IsEmpty]: Start isEmpty. Operand 49 states and 54 transitions. [2021-11-23 03:34:51,250 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 39 [2021-11-23 03:34:51,250 INFO L506 BasicCegarLoop]: Found error trace [2021-11-23 03:34:51,250 INFO L514 BasicCegarLoop]: trace histogram [14, 14, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2021-11-23 03:34:51,270 INFO L540 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (20)] Forceful destruction successful, exit code 0 [2021-11-23 03:34:51,451 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: 20 /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true,SelfDestructingSolverStorable22 [2021-11-23 03:34:51,451 INFO L402 AbstractCegarLoop]: === Iteration 24 === Targeting ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION === [ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2021-11-23 03:34:51,451 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2021-11-23 03:34:51,451 INFO L85 PathProgramCache]: Analyzing trace with hash -1972571246, now seen corresponding path program 18 times [2021-11-23 03:34:51,451 INFO L121 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2021-11-23 03:34:51,451 INFO L333 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1877268288] [2021-11-23 03:34:51,452 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:34:51,452 INFO L126 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2021-11-23 03:34:51,467 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:34:52,791 INFO L134 CoverageAnalysis]: Checked inductivity of 210 backedges. 0 proven. 210 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:34:52,792 INFO L139 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2021-11-23 03:34:52,792 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1877268288] [2021-11-23 03:34:52,792 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1877268288] provided 0 perfect and 1 imperfect interpolant sequences [2021-11-23 03:34:52,792 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1757739042] [2021-11-23 03:34:52,792 INFO L93 rtionOrderModulation]: Changing assertion order to TERMS_WITH_SMALL_CONSTANTS_FIRST [2021-11-23 03:34:52,792 INFO L168 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:34:52,792 INFO L189 MonitoredProcess]: No working directory specified, using /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 [2021-11-23 03:34:52,794 INFO L229 MonitoredProcess]: Starting monitored process 21 with /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2021-11-23 03:34:52,794 INFO L327 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (21)] Waiting until timeout for monitored process [2021-11-23 03:34:52,829 INFO L228 tOrderPrioritization]: Assert order TERMS_WITH_SMALL_CONSTANTS_FIRST issued 0 check-sat command(s) [2021-11-23 03:34:52,829 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2021-11-23 03:34:52,831 WARN L261 TraceCheckSpWp]: Trace formula consists of 160 conjuncts, 89 conjunts are in the unsatisfiable core [2021-11-23 03:34:52,833 INFO L286 TraceCheckSpWp]: Computing forward predicates... [2021-11-23 03:34:56,659 INFO L134 CoverageAnalysis]: Checked inductivity of 210 backedges. 0 proven. 210 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:34:56,659 INFO L328 TraceCheckSpWp]: Computing backward predicates... [2021-11-23 03:35:00,214 INFO L134 CoverageAnalysis]: Checked inductivity of 210 backedges. 0 proven. 210 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:35:00,215 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1757739042] provided 0 perfect and 2 imperfect interpolant sequences [2021-11-23 03:35:00,215 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [1109324394] [2021-11-23 03:35:00,216 INFO L159 IcfgInterpreter]: Started Sifa with 11 locations of interest [2021-11-23 03:35:00,216 INFO L166 IcfgInterpreter]: Building call graph [2021-11-23 03:35:00,216 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2021-11-23 03:35:00,216 INFO L176 IcfgInterpreter]: Starting interpretation [2021-11-23 03:35:00,217 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2021-11-23 03:35:00,364 INFO L180 IcfgInterpreter]: Interpretation finished [2021-11-23 03:35:02,227 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '9891#(and (<= 4 |ULTIMATE.start_correct_version_~i~0#1|) (<= |ULTIMATE.start_correct_version_#res#1| 1) (<= 4 |ULTIMATE.start_student_version_~w#1|) (<= |ULTIMATE.start_main_~is_divisible1~0#1| 1) (<= 4 |ULTIMATE.start_correct_version_~w#1|) (<= 4 |ULTIMATE.start_student_version_#in~w#1|) (<= 0 |ULTIMATE.start_correct_version_~is_divisible~0#1|) (<= |ULTIMATE.start_correct_version_~is_divisible~0#1| 1) (<= ~false~0 0) (<= |#NULL.offset| 0) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| 0) (<= 0 ~false~0) (<= 4 |ULTIMATE.start_correct_version_#in~w#1|) (<= 1 ~true~0) (<= 0 |ULTIMATE.start_correct_version_#res#1|) (or (and (not (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|)) (= |ULTIMATE.start_student_version_~is_divisible~1#1| ~false~0)) (and (<= 1 |ULTIMATE.start_student_version_~is_divisible~1#1|) (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (<= |ULTIMATE.start_student_version_~is_divisible~1#1| 1))) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (= (ite (= |ULTIMATE.start_main_~is_divisible1~0#1| |ULTIMATE.start_main_~is_divisible2~0#1|) 1 0) |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (<= 0 |ULTIMATE.start_main_~is_divisible1~0#1|) (<= ~true~0 1) (= |ULTIMATE.start_student_version_~is_divisible~1#1| |ULTIMATE.start_student_version_#res#1|) (<= 0 |#NULL.offset|) (<= 0 |#StackHeapBarrier|) (= |ULTIMATE.start_main_~is_divisible2~0#1| |ULTIMATE.start_student_version_#res#1|) (<= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (= |#NULL.base| 0))' at error location [2021-11-23 03:35:02,227 WARN L312 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2021-11-23 03:35:02,227 INFO L186 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2021-11-23 03:35:02,227 INFO L199 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [37, 37, 37] total 105 [2021-11-23 03:35:02,228 INFO L115 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [369022683] [2021-11-23 03:35:02,228 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2021-11-23 03:35:02,228 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 105 states [2021-11-23 03:35:02,228 INFO L103 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2021-11-23 03:35:02,228 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 105 interpolants. [2021-11-23 03:35:02,229 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=478, Invalid=12404, Unknown=0, NotChecked=0, Total=12882 [2021-11-23 03:35:02,229 INFO L87 Difference]: Start difference. First operand 49 states and 54 transitions. Second operand has 105 states, 105 states have (on average 1.0380952380952382) internal successors, (109), 105 states have internal predecessors, (109), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:35:30,744 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2021-11-23 03:35:30,744 INFO L93 Difference]: Finished difference Result 152 states and 171 transitions. [2021-11-23 03:35:30,744 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 92 states. [2021-11-23 03:35:30,745 INFO L78 Accepts]: Start accepts. Automaton has has 105 states, 105 states have (on average 1.0380952380952382) internal successors, (109), 105 states have internal predecessors, (109), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 38 [2021-11-23 03:35:30,745 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2021-11-23 03:35:30,745 INFO L225 Difference]: With dead ends: 152 [2021-11-23 03:35:30,746 INFO L226 Difference]: Without dead ends: 126 [2021-11-23 03:35:30,747 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 224 GetRequests, 36 SyntacticMatches, 1 SemanticMatches, 187 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 10340 ImplicationChecksByTransitivity, 34.6s TimeCoverageRelationStatistics Valid=1954, Invalid=33578, Unknown=0, NotChecked=0, Total=35532 [2021-11-23 03:35:30,748 INFO L933 BasicCegarLoop]: 2 mSDtfsCounter, 192 mSDsluCounter, 108 mSDsCounter, 0 mSdLazyCounter, 2606 mSolverCounterSat, 863 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 1.8s Time, 0 mProtectedPredicate, 0 mProtectedAction, 192 SdHoareTripleChecker+Valid, 103 SdHoareTripleChecker+Invalid, 3469 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 863 IncrementalHoareTripleChecker+Valid, 2606 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 2.1s IncrementalHoareTripleChecker+Time [2021-11-23 03:35:30,748 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [192 Valid, 103 Invalid, 3469 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [863 Valid, 2606 Invalid, 0 Unknown, 0 Unchecked, 2.1s Time] [2021-11-23 03:35:30,748 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 126 states. [2021-11-23 03:35:30,833 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 126 to 49. [2021-11-23 03:35:30,833 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 49 states, 48 states have (on average 1.1041666666666667) internal successors, (53), 48 states have internal predecessors, (53), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:35:30,834 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 49 states to 49 states and 53 transitions. [2021-11-23 03:35:30,834 INFO L78 Accepts]: Start accepts. Automaton has 49 states and 53 transitions. Word has length 38 [2021-11-23 03:35:30,834 INFO L84 Accepts]: Finished accepts. word is rejected. [2021-11-23 03:35:30,834 INFO L470 AbstractCegarLoop]: Abstraction has 49 states and 53 transitions. [2021-11-23 03:35:30,834 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 105 states, 105 states have (on average 1.0380952380952382) internal successors, (109), 105 states have internal predecessors, (109), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:35:30,835 INFO L276 IsEmpty]: Start isEmpty. Operand 49 states and 53 transitions. [2021-11-23 03:35:30,837 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 41 [2021-11-23 03:35:30,837 INFO L506 BasicCegarLoop]: Found error trace [2021-11-23 03:35:30,838 INFO L514 BasicCegarLoop]: trace histogram [15, 15, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2021-11-23 03:35:30,861 INFO L540 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (21)] Forceful destruction successful, exit code 0 [2021-11-23 03:35:31,049 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: 21 /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true,SelfDestructingSolverStorable23 [2021-11-23 03:35:31,050 INFO L402 AbstractCegarLoop]: === Iteration 25 === Targeting ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION === [ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2021-11-23 03:35:31,050 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2021-11-23 03:35:31,050 INFO L85 PathProgramCache]: Analyzing trace with hash -75648779, now seen corresponding path program 19 times [2021-11-23 03:35:31,050 INFO L121 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2021-11-23 03:35:31,050 INFO L333 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [780122726] [2021-11-23 03:35:31,050 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:35:31,050 INFO L126 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2021-11-23 03:35:31,065 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:35:32,646 INFO L134 CoverageAnalysis]: Checked inductivity of 240 backedges. 0 proven. 240 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:35:32,646 INFO L139 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2021-11-23 03:35:32,646 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [780122726] [2021-11-23 03:35:32,646 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [780122726] provided 0 perfect and 1 imperfect interpolant sequences [2021-11-23 03:35:32,646 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [120828435] [2021-11-23 03:35:32,646 INFO L93 rtionOrderModulation]: Changing assertion order to NOT_INCREMENTALLY [2021-11-23 03:35:32,647 INFO L168 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:35:32,647 INFO L189 MonitoredProcess]: No working directory specified, using /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 [2021-11-23 03:35:32,647 INFO L229 MonitoredProcess]: Starting monitored process 22 with /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2021-11-23 03:35:32,649 INFO L327 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (22)] Waiting until timeout for monitored process [2021-11-23 03:35:32,690 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:35:32,692 WARN L261 TraceCheckSpWp]: Trace formula consists of 166 conjuncts, 93 conjunts are in the unsatisfiable core [2021-11-23 03:35:32,693 INFO L286 TraceCheckSpWp]: Computing forward predicates... [2021-11-23 03:35:37,140 INFO L134 CoverageAnalysis]: Checked inductivity of 240 backedges. 0 proven. 240 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:35:37,140 INFO L328 TraceCheckSpWp]: Computing backward predicates... [2021-11-23 03:35:41,075 INFO L134 CoverageAnalysis]: Checked inductivity of 240 backedges. 0 proven. 240 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:35:41,075 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleZ3 [120828435] provided 0 perfect and 2 imperfect interpolant sequences [2021-11-23 03:35:41,076 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [1187354051] [2021-11-23 03:35:41,077 INFO L159 IcfgInterpreter]: Started Sifa with 11 locations of interest [2021-11-23 03:35:41,077 INFO L166 IcfgInterpreter]: Building call graph [2021-11-23 03:35:41,077 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2021-11-23 03:35:41,078 INFO L176 IcfgInterpreter]: Starting interpretation [2021-11-23 03:35:41,078 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2021-11-23 03:35:41,227 INFO L180 IcfgInterpreter]: Interpretation finished [2021-11-23 03:35:43,163 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '10767#(and (<= 4 |ULTIMATE.start_correct_version_~i~0#1|) (<= |ULTIMATE.start_correct_version_#res#1| 1) (<= 4 |ULTIMATE.start_student_version_~w#1|) (<= |ULTIMATE.start_main_~is_divisible1~0#1| 1) (<= 4 |ULTIMATE.start_correct_version_~w#1|) (<= 4 |ULTIMATE.start_student_version_#in~w#1|) (<= 0 |ULTIMATE.start_correct_version_~is_divisible~0#1|) (<= |ULTIMATE.start_correct_version_~is_divisible~0#1| 1) (<= ~false~0 0) (<= |#NULL.offset| 0) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| 0) (<= 0 ~false~0) (<= 4 |ULTIMATE.start_correct_version_#in~w#1|) (<= 1 ~true~0) (<= 0 |ULTIMATE.start_correct_version_#res#1|) (or (and (not (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|)) (= |ULTIMATE.start_student_version_~is_divisible~1#1| ~false~0)) (and (<= 1 |ULTIMATE.start_student_version_~is_divisible~1#1|) (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (<= |ULTIMATE.start_student_version_~is_divisible~1#1| 1))) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (= (ite (= |ULTIMATE.start_main_~is_divisible1~0#1| |ULTIMATE.start_main_~is_divisible2~0#1|) 1 0) |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (<= 0 |ULTIMATE.start_main_~is_divisible1~0#1|) (<= ~true~0 1) (= |ULTIMATE.start_student_version_~is_divisible~1#1| |ULTIMATE.start_student_version_#res#1|) (<= 0 |#NULL.offset|) (<= 0 |#StackHeapBarrier|) (= |ULTIMATE.start_main_~is_divisible2~0#1| |ULTIMATE.start_student_version_#res#1|) (<= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (= |#NULL.base| 0))' at error location [2021-11-23 03:35:43,164 WARN L312 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2021-11-23 03:35:43,164 INFO L186 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2021-11-23 03:35:43,164 INFO L199 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [39, 39, 39] total 111 [2021-11-23 03:35:43,164 INFO L115 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1361540612] [2021-11-23 03:35:43,165 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2021-11-23 03:35:43,165 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 111 states [2021-11-23 03:35:43,165 INFO L103 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2021-11-23 03:35:43,165 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 111 interpolants. [2021-11-23 03:35:43,166 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=505, Invalid=13775, Unknown=0, NotChecked=0, Total=14280 [2021-11-23 03:35:43,166 INFO L87 Difference]: Start difference. First operand 49 states and 53 transitions. Second operand has 111 states, 111 states have (on average 1.0360360360360361) internal successors, (115), 111 states have internal predecessors, (115), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:36:15,847 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2021-11-23 03:36:15,847 INFO L93 Difference]: Finished difference Result 156 states and 176 transitions. [2021-11-23 03:36:15,847 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 97 states. [2021-11-23 03:36:15,847 INFO L78 Accepts]: Start accepts. Automaton has has 111 states, 111 states have (on average 1.0360360360360361) internal successors, (115), 111 states have internal predecessors, (115), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 40 [2021-11-23 03:36:15,847 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2021-11-23 03:36:15,848 INFO L225 Difference]: With dead ends: 156 [2021-11-23 03:36:15,848 INFO L226 Difference]: Without dead ends: 129 [2021-11-23 03:36:15,850 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 236 GetRequests, 38 SyntacticMatches, 1 SemanticMatches, 197 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 11507 ImplicationChecksByTransitivity, 39.2s TimeCoverageRelationStatistics Valid=2098, Invalid=37304, Unknown=0, NotChecked=0, Total=39402 [2021-11-23 03:36:15,850 INFO L933 BasicCegarLoop]: 2 mSDtfsCounter, 196 mSDsluCounter, 136 mSDsCounter, 0 mSdLazyCounter, 3441 mSolverCounterSat, 935 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 2.4s Time, 0 mProtectedPredicate, 0 mProtectedAction, 196 SdHoareTripleChecker+Valid, 131 SdHoareTripleChecker+Invalid, 4376 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 935 IncrementalHoareTripleChecker+Valid, 3441 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 2.8s IncrementalHoareTripleChecker+Time [2021-11-23 03:36:15,851 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [196 Valid, 131 Invalid, 4376 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [935 Valid, 3441 Invalid, 0 Unknown, 0 Unchecked, 2.8s Time] [2021-11-23 03:36:15,851 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 129 states. [2021-11-23 03:36:15,940 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 129 to 49. [2021-11-23 03:36:15,940 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 49 states, 48 states have (on average 1.0833333333333333) internal successors, (52), 48 states have internal predecessors, (52), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:36:15,940 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 49 states to 49 states and 52 transitions. [2021-11-23 03:36:15,940 INFO L78 Accepts]: Start accepts. Automaton has 49 states and 52 transitions. Word has length 40 [2021-11-23 03:36:15,940 INFO L84 Accepts]: Finished accepts. word is rejected. [2021-11-23 03:36:15,941 INFO L470 AbstractCegarLoop]: Abstraction has 49 states and 52 transitions. [2021-11-23 03:36:15,941 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 111 states, 111 states have (on average 1.0360360360360361) internal successors, (115), 111 states have internal predecessors, (115), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:36:15,941 INFO L276 IsEmpty]: Start isEmpty. Operand 49 states and 52 transitions. [2021-11-23 03:36:15,941 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 43 [2021-11-23 03:36:15,941 INFO L506 BasicCegarLoop]: Found error trace [2021-11-23 03:36:15,942 INFO L514 BasicCegarLoop]: trace histogram [16, 16, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2021-11-23 03:36:15,965 INFO L540 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (22)] Forceful destruction successful, exit code 0 [2021-11-23 03:36:16,149 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: 22 /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true,SelfDestructingSolverStorable24 [2021-11-23 03:36:16,149 INFO L402 AbstractCegarLoop]: === Iteration 26 === Targeting ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION === [ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2021-11-23 03:36:16,150 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2021-11-23 03:36:16,150 INFO L85 PathProgramCache]: Analyzing trace with hash 13500146, now seen corresponding path program 20 times [2021-11-23 03:36:16,150 INFO L121 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2021-11-23 03:36:16,150 INFO L333 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1730095509] [2021-11-23 03:36:16,150 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:36:16,150 INFO L126 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2021-11-23 03:36:16,176 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:36:18,024 INFO L134 CoverageAnalysis]: Checked inductivity of 272 backedges. 0 proven. 272 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:36:18,025 INFO L139 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2021-11-23 03:36:18,025 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1730095509] [2021-11-23 03:36:18,025 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1730095509] provided 0 perfect and 1 imperfect interpolant sequences [2021-11-23 03:36:18,025 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [651468505] [2021-11-23 03:36:18,025 INFO L93 rtionOrderModulation]: Changing assertion order to OUTSIDE_LOOP_FIRST2 [2021-11-23 03:36:18,025 INFO L168 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:36:18,025 INFO L189 MonitoredProcess]: No working directory specified, using /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 [2021-11-23 03:36:18,026 INFO L229 MonitoredProcess]: Starting monitored process 23 with /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2021-11-23 03:36:18,027 INFO L327 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (23)] Waiting until timeout for monitored process [2021-11-23 03:36:18,073 INFO L228 tOrderPrioritization]: Assert order OUTSIDE_LOOP_FIRST2 issued 9 check-sat command(s) [2021-11-23 03:36:18,073 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2021-11-23 03:36:18,076 WARN L261 TraceCheckSpWp]: Trace formula consists of 172 conjuncts, 99 conjunts are in the unsatisfiable core [2021-11-23 03:36:18,077 INFO L286 TraceCheckSpWp]: Computing forward predicates... [2021-11-23 03:36:23,077 INFO L134 CoverageAnalysis]: Checked inductivity of 272 backedges. 0 proven. 272 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:36:23,077 INFO L328 TraceCheckSpWp]: Computing backward predicates... [2021-11-23 03:36:27,926 INFO L134 CoverageAnalysis]: Checked inductivity of 272 backedges. 0 proven. 272 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:36:27,926 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleZ3 [651468505] provided 0 perfect and 2 imperfect interpolant sequences [2021-11-23 03:36:27,926 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [552748094] [2021-11-23 03:36:27,927 INFO L159 IcfgInterpreter]: Started Sifa with 11 locations of interest [2021-11-23 03:36:27,927 INFO L166 IcfgInterpreter]: Building call graph [2021-11-23 03:36:27,928 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2021-11-23 03:36:27,928 INFO L176 IcfgInterpreter]: Starting interpretation [2021-11-23 03:36:27,928 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2021-11-23 03:36:28,050 INFO L180 IcfgInterpreter]: Interpretation finished [2021-11-23 03:36:29,827 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '11678#(and (<= 4 |ULTIMATE.start_correct_version_~i~0#1|) (<= |ULTIMATE.start_correct_version_#res#1| 1) (<= 4 |ULTIMATE.start_student_version_~w#1|) (<= |ULTIMATE.start_main_~is_divisible1~0#1| 1) (<= 4 |ULTIMATE.start_correct_version_~w#1|) (<= 4 |ULTIMATE.start_student_version_#in~w#1|) (<= 0 |ULTIMATE.start_correct_version_~is_divisible~0#1|) (= ~true~0 1) (<= |ULTIMATE.start_correct_version_~is_divisible~0#1| 1) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| 0) (<= 4 |ULTIMATE.start_correct_version_#in~w#1|) (= ~false~0 0) (<= 0 |ULTIMATE.start_correct_version_#res#1|) (or (and (not (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|)) (= |ULTIMATE.start_student_version_~is_divisible~1#1| ~false~0)) (and (<= 1 |ULTIMATE.start_student_version_~is_divisible~1#1|) (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (<= |ULTIMATE.start_student_version_~is_divisible~1#1| 1))) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (= |#NULL.offset| 0) (= (ite (= |ULTIMATE.start_main_~is_divisible1~0#1| |ULTIMATE.start_main_~is_divisible2~0#1|) 1 0) |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (<= 0 |ULTIMATE.start_main_~is_divisible1~0#1|) (= |ULTIMATE.start_student_version_~is_divisible~1#1| |ULTIMATE.start_student_version_#res#1|) (<= 0 |#StackHeapBarrier|) (= |ULTIMATE.start_main_~is_divisible2~0#1| |ULTIMATE.start_student_version_#res#1|) (<= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (= |#NULL.base| 0))' at error location [2021-11-23 03:36:29,827 WARN L312 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2021-11-23 03:36:29,827 INFO L186 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2021-11-23 03:36:29,827 INFO L199 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [41, 41, 41] total 118 [2021-11-23 03:36:29,828 INFO L115 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [835722850] [2021-11-23 03:36:29,828 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2021-11-23 03:36:29,828 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 118 states [2021-11-23 03:36:29,828 INFO L103 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2021-11-23 03:36:29,829 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 118 interpolants. [2021-11-23 03:36:29,830 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=535, Invalid=15467, Unknown=0, NotChecked=0, Total=16002 [2021-11-23 03:36:29,830 INFO L87 Difference]: Start difference. First operand 49 states and 52 transitions. Second operand has 118 states, 118 states have (on average 1.0338983050847457) internal successors, (122), 118 states have internal predecessors, (122), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:36:54,878 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2021-11-23 03:36:54,879 INFO L93 Difference]: Finished difference Result 160 states and 181 transitions. [2021-11-23 03:36:54,879 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 102 states. [2021-11-23 03:36:54,879 INFO L78 Accepts]: Start accepts. Automaton has has 118 states, 118 states have (on average 1.0338983050847457) internal successors, (122), 118 states have internal predecessors, (122), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 42 [2021-11-23 03:36:54,879 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2021-11-23 03:36:54,880 INFO L225 Difference]: With dead ends: 160 [2021-11-23 03:36:54,880 INFO L226 Difference]: Without dead ends: 132 [2021-11-23 03:36:54,883 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 248 GetRequests, 39 SyntacticMatches, 1 SemanticMatches, 208 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 12918 ImplicationChecksByTransitivity, 32.2s TimeCoverageRelationStatistics Valid=2251, Invalid=41639, Unknown=0, NotChecked=0, Total=43890 [2021-11-23 03:36:54,883 INFO L933 BasicCegarLoop]: 2 mSDtfsCounter, 208 mSDsluCounter, 132 mSDsCounter, 0 mSdLazyCounter, 3619 mSolverCounterSat, 1057 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 2.6s Time, 0 mProtectedPredicate, 0 mProtectedAction, 208 SdHoareTripleChecker+Valid, 129 SdHoareTripleChecker+Invalid, 4676 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 1057 IncrementalHoareTripleChecker+Valid, 3619 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 3.0s IncrementalHoareTripleChecker+Time [2021-11-23 03:36:54,884 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [208 Valid, 129 Invalid, 4676 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [1057 Valid, 3619 Invalid, 0 Unknown, 0 Unchecked, 3.0s Time] [2021-11-23 03:36:54,884 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 132 states. [2021-11-23 03:36:54,993 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 132 to 49. [2021-11-23 03:36:54,993 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 49 states, 48 states have (on average 1.0625) internal successors, (51), 48 states have internal predecessors, (51), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:36:54,994 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 49 states to 49 states and 51 transitions. [2021-11-23 03:36:54,994 INFO L78 Accepts]: Start accepts. Automaton has 49 states and 51 transitions. Word has length 42 [2021-11-23 03:36:54,994 INFO L84 Accepts]: Finished accepts. word is rejected. [2021-11-23 03:36:54,994 INFO L470 AbstractCegarLoop]: Abstraction has 49 states and 51 transitions. [2021-11-23 03:36:54,994 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 118 states, 118 states have (on average 1.0338983050847457) internal successors, (122), 118 states have internal predecessors, (122), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:36:54,995 INFO L276 IsEmpty]: Start isEmpty. Operand 49 states and 51 transitions. [2021-11-23 03:36:54,995 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 45 [2021-11-23 03:36:54,995 INFO L506 BasicCegarLoop]: Found error trace [2021-11-23 03:36:54,996 INFO L514 BasicCegarLoop]: trace histogram [17, 17, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2021-11-23 03:36:55,032 INFO L540 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (23)] Forceful destruction successful, exit code 0 [2021-11-23 03:36:55,217 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: 23 /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true,SelfDestructingSolverStorable25 [2021-11-23 03:36:55,218 INFO L402 AbstractCegarLoop]: === Iteration 27 === Targeting ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION === [ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2021-11-23 03:36:55,218 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2021-11-23 03:36:55,218 INFO L85 PathProgramCache]: Analyzing trace with hash 217386901, now seen corresponding path program 21 times [2021-11-23 03:36:55,218 INFO L121 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2021-11-23 03:36:55,218 INFO L333 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [485952287] [2021-11-23 03:36:55,218 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:36:55,218 INFO L126 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2021-11-23 03:36:55,231 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:36:56,986 INFO L134 CoverageAnalysis]: Checked inductivity of 306 backedges. 0 proven. 306 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:36:56,986 INFO L139 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2021-11-23 03:36:56,986 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [485952287] [2021-11-23 03:36:56,986 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [485952287] provided 0 perfect and 1 imperfect interpolant sequences [2021-11-23 03:36:56,987 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [2135889257] [2021-11-23 03:36:56,987 INFO L93 rtionOrderModulation]: Changing assertion order to TERMS_WITH_SMALL_CONSTANTS_FIRST [2021-11-23 03:36:56,987 INFO L168 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:36:56,987 INFO L189 MonitoredProcess]: No working directory specified, using /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 [2021-11-23 03:36:56,992 INFO L229 MonitoredProcess]: Starting monitored process 24 with /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2021-11-23 03:36:56,993 INFO L327 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (24)] Waiting until timeout for monitored process [2021-11-23 03:36:57,034 INFO L228 tOrderPrioritization]: Assert order TERMS_WITH_SMALL_CONSTANTS_FIRST issued 0 check-sat command(s) [2021-11-23 03:36:57,034 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2021-11-23 03:36:57,036 WARN L261 TraceCheckSpWp]: Trace formula consists of 178 conjuncts, 101 conjunts are in the unsatisfiable core [2021-11-23 03:36:57,037 INFO L286 TraceCheckSpWp]: Computing forward predicates... [2021-11-23 03:37:02,069 INFO L134 CoverageAnalysis]: Checked inductivity of 306 backedges. 0 proven. 306 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:37:02,069 INFO L328 TraceCheckSpWp]: Computing backward predicates... [2021-11-23 03:37:06,809 INFO L134 CoverageAnalysis]: Checked inductivity of 306 backedges. 0 proven. 306 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:37:06,809 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleZ3 [2135889257] provided 0 perfect and 2 imperfect interpolant sequences [2021-11-23 03:37:06,809 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [361143913] [2021-11-23 03:37:06,810 INFO L159 IcfgInterpreter]: Started Sifa with 11 locations of interest [2021-11-23 03:37:06,811 INFO L166 IcfgInterpreter]: Building call graph [2021-11-23 03:37:06,811 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2021-11-23 03:37:06,811 INFO L176 IcfgInterpreter]: Starting interpretation [2021-11-23 03:37:06,811 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2021-11-23 03:37:06,977 INFO L180 IcfgInterpreter]: Interpretation finished [2021-11-23 03:37:09,133 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '12622#(and (<= 4 |ULTIMATE.start_correct_version_~i~0#1|) (<= |ULTIMATE.start_correct_version_#res#1| 1) (<= 4 |ULTIMATE.start_student_version_~w#1|) (<= |ULTIMATE.start_main_~is_divisible1~0#1| 1) (<= 4 |ULTIMATE.start_correct_version_~w#1|) (<= 4 |ULTIMATE.start_student_version_#in~w#1|) (<= 0 |ULTIMATE.start_correct_version_~is_divisible~0#1|) (<= |ULTIMATE.start_correct_version_~is_divisible~0#1| 1) (<= ~false~0 0) (<= |#NULL.offset| 0) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| 0) (<= 0 ~false~0) (<= 4 |ULTIMATE.start_correct_version_#in~w#1|) (<= 1 ~true~0) (<= 0 |ULTIMATE.start_correct_version_#res#1|) (or (and (not (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|)) (= |ULTIMATE.start_student_version_~is_divisible~1#1| ~false~0)) (and (<= 1 |ULTIMATE.start_student_version_~is_divisible~1#1|) (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (<= |ULTIMATE.start_student_version_~is_divisible~1#1| 1))) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (= (ite (= |ULTIMATE.start_main_~is_divisible1~0#1| |ULTIMATE.start_main_~is_divisible2~0#1|) 1 0) |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (<= 0 |ULTIMATE.start_main_~is_divisible1~0#1|) (<= ~true~0 1) (= |ULTIMATE.start_student_version_~is_divisible~1#1| |ULTIMATE.start_student_version_#res#1|) (<= 0 |#NULL.offset|) (<= 0 |#StackHeapBarrier|) (= |ULTIMATE.start_main_~is_divisible2~0#1| |ULTIMATE.start_student_version_#res#1|) (<= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (= |#NULL.base| 0))' at error location [2021-11-23 03:37:09,133 WARN L312 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2021-11-23 03:37:09,133 INFO L186 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2021-11-23 03:37:09,133 INFO L199 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [43, 43, 43] total 123 [2021-11-23 03:37:09,133 INFO L115 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1262360072] [2021-11-23 03:37:09,134 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2021-11-23 03:37:09,134 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 123 states [2021-11-23 03:37:09,134 INFO L103 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2021-11-23 03:37:09,134 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 123 interpolants. [2021-11-23 03:37:09,135 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=559, Invalid=16733, Unknown=0, NotChecked=0, Total=17292 [2021-11-23 03:37:09,135 INFO L87 Difference]: Start difference. First operand 49 states and 51 transitions. Second operand has 123 states, 123 states have (on average 1.032520325203252) internal successors, (127), 123 states have internal predecessors, (127), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:37:50,452 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2021-11-23 03:37:50,452 INFO L93 Difference]: Finished difference Result 142 states and 163 transitions. [2021-11-23 03:37:50,452 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 105 states. [2021-11-23 03:37:50,452 INFO L78 Accepts]: Start accepts. Automaton has has 123 states, 123 states have (on average 1.032520325203252) internal successors, (127), 123 states have internal predecessors, (127), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 44 [2021-11-23 03:37:50,452 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2021-11-23 03:37:50,453 INFO L225 Difference]: With dead ends: 142 [2021-11-23 03:37:50,453 INFO L226 Difference]: Without dead ends: 115 [2021-11-23 03:37:50,456 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 258 GetRequests, 42 SyntacticMatches, 1 SemanticMatches, 215 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 13744 ImplicationChecksByTransitivity, 48.7s TimeCoverageRelationStatistics Valid=2325, Invalid=44547, Unknown=0, NotChecked=0, Total=46872 [2021-11-23 03:37:50,457 INFO L933 BasicCegarLoop]: 2 mSDtfsCounter, 183 mSDsluCounter, 171 mSDsCounter, 0 mSdLazyCounter, 4291 mSolverCounterSat, 1093 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 2.9s Time, 0 mProtectedPredicate, 0 mProtectedAction, 183 SdHoareTripleChecker+Valid, 150 SdHoareTripleChecker+Invalid, 5384 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 1093 IncrementalHoareTripleChecker+Valid, 4291 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 3.4s IncrementalHoareTripleChecker+Time [2021-11-23 03:37:50,458 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [183 Valid, 150 Invalid, 5384 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [1093 Valid, 4291 Invalid, 0 Unknown, 0 Unchecked, 3.4s Time] [2021-11-23 03:37:50,458 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 115 states. [2021-11-23 03:37:50,557 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 115 to 47. [2021-11-23 03:37:50,558 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 47 states, 46 states have (on average 1.0434782608695652) internal successors, (48), 46 states have internal predecessors, (48), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:37:50,558 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 47 states to 47 states and 48 transitions. [2021-11-23 03:37:50,558 INFO L78 Accepts]: Start accepts. Automaton has 47 states and 48 transitions. Word has length 44 [2021-11-23 03:37:50,558 INFO L84 Accepts]: Finished accepts. word is rejected. [2021-11-23 03:37:50,558 INFO L470 AbstractCegarLoop]: Abstraction has 47 states and 48 transitions. [2021-11-23 03:37:50,558 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 123 states, 123 states have (on average 1.032520325203252) internal successors, (127), 123 states have internal predecessors, (127), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:37:50,559 INFO L276 IsEmpty]: Start isEmpty. Operand 47 states and 48 transitions. [2021-11-23 03:37:50,559 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 47 [2021-11-23 03:37:50,559 INFO L506 BasicCegarLoop]: Found error trace [2021-11-23 03:37:50,559 INFO L514 BasicCegarLoop]: trace histogram [18, 18, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2021-11-23 03:37:50,580 INFO L540 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (24)] Forceful destruction successful, exit code 0 [2021-11-23 03:37:50,759 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable26,24 /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:37:50,760 INFO L402 AbstractCegarLoop]: === Iteration 28 === Targeting ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION === [ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2021-11-23 03:37:50,760 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2021-11-23 03:37:50,760 INFO L85 PathProgramCache]: Analyzing trace with hash -936250798, now seen corresponding path program 22 times [2021-11-23 03:37:50,760 INFO L121 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2021-11-23 03:37:50,760 INFO L333 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1913033888] [2021-11-23 03:37:50,760 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:37:50,760 INFO L126 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2021-11-23 03:37:50,775 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:37:52,538 INFO L134 CoverageAnalysis]: Checked inductivity of 342 backedges. 0 proven. 342 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:37:52,538 INFO L139 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2021-11-23 03:37:52,538 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1913033888] [2021-11-23 03:37:52,538 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1913033888] provided 0 perfect and 1 imperfect interpolant sequences [2021-11-23 03:37:52,538 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [525778776] [2021-11-23 03:37:52,538 INFO L93 rtionOrderModulation]: Changing assertion order to NOT_INCREMENTALLY [2021-11-23 03:37:52,538 INFO L168 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:37:52,539 INFO L189 MonitoredProcess]: No working directory specified, using /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 [2021-11-23 03:37:52,539 INFO L229 MonitoredProcess]: Starting monitored process 25 with /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2021-11-23 03:37:52,541 INFO L327 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (25)] Waiting until timeout for monitored process [2021-11-23 03:37:52,581 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:37:52,583 WARN L261 TraceCheckSpWp]: Trace formula consists of 184 conjuncts, 105 conjunts are in the unsatisfiable core [2021-11-23 03:37:52,584 INFO L286 TraceCheckSpWp]: Computing forward predicates... [2021-11-23 03:37:58,150 INFO L134 CoverageAnalysis]: Checked inductivity of 342 backedges. 0 proven. 342 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:37:58,150 INFO L328 TraceCheckSpWp]: Computing backward predicates... [2021-11-23 03:38:03,477 INFO L134 CoverageAnalysis]: Checked inductivity of 342 backedges. 0 proven. 342 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:38:03,477 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleZ3 [525778776] provided 0 perfect and 2 imperfect interpolant sequences [2021-11-23 03:38:03,477 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [1687045908] [2021-11-23 03:38:03,478 INFO L159 IcfgInterpreter]: Started Sifa with 11 locations of interest [2021-11-23 03:38:03,478 INFO L166 IcfgInterpreter]: Building call graph [2021-11-23 03:38:03,478 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2021-11-23 03:38:03,478 INFO L176 IcfgInterpreter]: Starting interpretation [2021-11-23 03:38:03,479 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2021-11-23 03:38:03,634 INFO L180 IcfgInterpreter]: Interpretation finished [2021-11-23 03:38:05,907 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '13551#(and (<= 4 |ULTIMATE.start_correct_version_~i~0#1|) (<= |ULTIMATE.start_correct_version_#res#1| 1) (<= 4 |ULTIMATE.start_student_version_~w#1|) (<= |ULTIMATE.start_main_~is_divisible1~0#1| 1) (<= 4 |ULTIMATE.start_correct_version_~w#1|) (<= 4 |ULTIMATE.start_student_version_#in~w#1|) (<= 0 |ULTIMATE.start_correct_version_~is_divisible~0#1|) (<= |ULTIMATE.start_correct_version_~is_divisible~0#1| 1) (<= ~false~0 0) (<= |#NULL.offset| 0) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| 0) (<= 0 ~false~0) (<= 4 |ULTIMATE.start_correct_version_#in~w#1|) (<= 1 ~true~0) (<= 0 |ULTIMATE.start_correct_version_#res#1|) (or (and (not (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|)) (= |ULTIMATE.start_student_version_~is_divisible~1#1| ~false~0)) (and (<= 1 |ULTIMATE.start_student_version_~is_divisible~1#1|) (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (<= |ULTIMATE.start_student_version_~is_divisible~1#1| 1))) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (= (ite (= |ULTIMATE.start_main_~is_divisible1~0#1| |ULTIMATE.start_main_~is_divisible2~0#1|) 1 0) |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (<= 0 |ULTIMATE.start_main_~is_divisible1~0#1|) (<= ~true~0 1) (= |ULTIMATE.start_student_version_~is_divisible~1#1| |ULTIMATE.start_student_version_#res#1|) (<= 0 |#NULL.offset|) (<= 0 |#StackHeapBarrier|) (= |ULTIMATE.start_main_~is_divisible2~0#1| |ULTIMATE.start_student_version_#res#1|) (<= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (= |#NULL.base| 0))' at error location [2021-11-23 03:38:05,907 WARN L312 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2021-11-23 03:38:05,907 INFO L186 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2021-11-23 03:38:05,908 INFO L199 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [45, 45, 45] total 129 [2021-11-23 03:38:05,908 INFO L115 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1195820717] [2021-11-23 03:38:05,908 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2021-11-23 03:38:05,908 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 129 states [2021-11-23 03:38:05,908 INFO L103 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2021-11-23 03:38:05,909 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 129 interpolants. [2021-11-23 03:38:05,910 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=586, Invalid=18320, Unknown=0, NotChecked=0, Total=18906 [2021-11-23 03:38:05,910 INFO L87 Difference]: Start difference. First operand 47 states and 48 transitions. Second operand has 129 states, 129 states have (on average 1.0310077519379846) internal successors, (133), 129 states have internal predecessors, (133), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:38:54,238 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2021-11-23 03:38:54,239 INFO L93 Difference]: Finished difference Result 151 states and 175 transitions. [2021-11-23 03:38:54,239 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 114 states. [2021-11-23 03:38:54,239 INFO L78 Accepts]: Start accepts. Automaton has has 129 states, 129 states have (on average 1.0310077519379846) internal successors, (133), 129 states have internal predecessors, (133), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 46 [2021-11-23 03:38:54,240 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2021-11-23 03:38:54,241 INFO L225 Difference]: With dead ends: 151 [2021-11-23 03:38:54,241 INFO L226 Difference]: Without dead ends: 119 [2021-11-23 03:38:54,245 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 274 GetRequests, 44 SyntacticMatches, 1 SemanticMatches, 229 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 15677 ImplicationChecksByTransitivity, 56.5s TimeCoverageRelationStatistics Valid=2593, Invalid=50537, Unknown=0, NotChecked=0, Total=53130 [2021-11-23 03:38:54,246 INFO L933 BasicCegarLoop]: 2 mSDtfsCounter, 229 mSDsluCounter, 158 mSDsCounter, 0 mSdLazyCounter, 4286 mSolverCounterSat, 1315 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 3.2s Time, 0 mProtectedPredicate, 0 mProtectedAction, 229 SdHoareTripleChecker+Valid, 154 SdHoareTripleChecker+Invalid, 5601 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 1315 IncrementalHoareTripleChecker+Valid, 4286 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 3.7s IncrementalHoareTripleChecker+Time [2021-11-23 03:38:54,246 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [229 Valid, 154 Invalid, 5601 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [1315 Valid, 4286 Invalid, 0 Unknown, 0 Unchecked, 3.7s Time] [2021-11-23 03:38:54,247 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 119 states. [2021-11-23 03:38:54,434 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 119 to 70. [2021-11-23 03:38:54,434 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 70 states, 69 states have (on average 1.3043478260869565) internal successors, (90), 69 states have internal predecessors, (90), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:38:54,435 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 70 states to 70 states and 90 transitions. [2021-11-23 03:38:54,435 INFO L78 Accepts]: Start accepts. Automaton has 70 states and 90 transitions. Word has length 46 [2021-11-23 03:38:54,435 INFO L84 Accepts]: Finished accepts. word is rejected. [2021-11-23 03:38:54,435 INFO L470 AbstractCegarLoop]: Abstraction has 70 states and 90 transitions. [2021-11-23 03:38:54,435 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 129 states, 129 states have (on average 1.0310077519379846) internal successors, (133), 129 states have internal predecessors, (133), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:38:54,435 INFO L276 IsEmpty]: Start isEmpty. Operand 70 states and 90 transitions. [2021-11-23 03:38:54,436 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 49 [2021-11-23 03:38:54,436 INFO L506 BasicCegarLoop]: Found error trace [2021-11-23 03:38:54,436 INFO L514 BasicCegarLoop]: trace histogram [19, 19, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2021-11-23 03:38:54,459 INFO L540 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (25)] Forceful destruction successful, exit code 0 [2021-11-23 03:38:54,636 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: 25 /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true,SelfDestructingSolverStorable27 [2021-11-23 03:38:54,637 INFO L402 AbstractCegarLoop]: === Iteration 29 === Targeting ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION === [ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2021-11-23 03:38:54,637 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2021-11-23 03:38:54,637 INFO L85 PathProgramCache]: Analyzing trace with hash 504858165, now seen corresponding path program 23 times [2021-11-23 03:38:54,637 INFO L121 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2021-11-23 03:38:54,637 INFO L333 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [2028650733] [2021-11-23 03:38:54,637 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:38:54,637 INFO L126 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2021-11-23 03:38:54,654 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:38:56,757 INFO L134 CoverageAnalysis]: Checked inductivity of 380 backedges. 0 proven. 380 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:38:56,757 INFO L139 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2021-11-23 03:38:56,757 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [2028650733] [2021-11-23 03:38:56,757 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [2028650733] provided 0 perfect and 1 imperfect interpolant sequences [2021-11-23 03:38:56,757 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [822996046] [2021-11-23 03:38:56,757 INFO L93 rtionOrderModulation]: Changing assertion order to OUTSIDE_LOOP_FIRST2 [2021-11-23 03:38:56,757 INFO L168 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:38:56,758 INFO L189 MonitoredProcess]: No working directory specified, using /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 [2021-11-23 03:38:56,758 INFO L229 MonitoredProcess]: Starting monitored process 26 with /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2021-11-23 03:38:56,759 INFO L327 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (26)] Waiting until timeout for monitored process [2021-11-23 03:38:56,808 INFO L228 tOrderPrioritization]: Assert order OUTSIDE_LOOP_FIRST2 issued 11 check-sat command(s) [2021-11-23 03:38:56,808 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2021-11-23 03:38:56,810 WARN L261 TraceCheckSpWp]: Trace formula consists of 190 conjuncts, 111 conjunts are in the unsatisfiable core [2021-11-23 03:38:56,812 INFO L286 TraceCheckSpWp]: Computing forward predicates... [2021-11-23 03:39:03,346 INFO L134 CoverageAnalysis]: Checked inductivity of 380 backedges. 0 proven. 380 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:39:03,346 INFO L328 TraceCheckSpWp]: Computing backward predicates... [2021-11-23 03:39:10,717 INFO L134 CoverageAnalysis]: Checked inductivity of 380 backedges. 0 proven. 380 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:39:10,718 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleZ3 [822996046] provided 0 perfect and 2 imperfect interpolant sequences [2021-11-23 03:39:10,718 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [994114295] [2021-11-23 03:39:10,719 INFO L159 IcfgInterpreter]: Started Sifa with 11 locations of interest [2021-11-23 03:39:10,719 INFO L166 IcfgInterpreter]: Building call graph [2021-11-23 03:39:10,719 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2021-11-23 03:39:10,720 INFO L176 IcfgInterpreter]: Starting interpretation [2021-11-23 03:39:10,720 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2021-11-23 03:39:10,899 INFO L180 IcfgInterpreter]: Interpretation finished [2021-11-23 03:39:13,478 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '14576#(and (<= 4 |ULTIMATE.start_correct_version_~i~0#1|) (<= |ULTIMATE.start_correct_version_#res#1| 1) (<= 4 |ULTIMATE.start_student_version_~w#1|) (<= |ULTIMATE.start_main_~is_divisible1~0#1| 1) (<= 4 |ULTIMATE.start_correct_version_~w#1|) (<= 4 |ULTIMATE.start_student_version_#in~w#1|) (<= 0 |ULTIMATE.start_correct_version_~is_divisible~0#1|) (<= |ULTIMATE.start_correct_version_~is_divisible~0#1| 1) (<= ~false~0 0) (<= |#NULL.offset| 0) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| 0) (<= 0 ~false~0) (<= 4 |ULTIMATE.start_correct_version_#in~w#1|) (<= 1 ~true~0) (<= 0 |ULTIMATE.start_correct_version_#res#1|) (or (and (not (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|)) (= |ULTIMATE.start_student_version_~is_divisible~1#1| ~false~0)) (and (<= 1 |ULTIMATE.start_student_version_~is_divisible~1#1|) (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (<= |ULTIMATE.start_student_version_~is_divisible~1#1| 1))) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (= (ite (= |ULTIMATE.start_main_~is_divisible1~0#1| |ULTIMATE.start_main_~is_divisible2~0#1|) 1 0) |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (<= 0 |ULTIMATE.start_main_~is_divisible1~0#1|) (<= ~true~0 1) (= |ULTIMATE.start_student_version_~is_divisible~1#1| |ULTIMATE.start_student_version_#res#1|) (<= 0 |#NULL.offset|) (<= 0 |#StackHeapBarrier|) (= |ULTIMATE.start_main_~is_divisible2~0#1| |ULTIMATE.start_student_version_#res#1|) (<= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (= |#NULL.base| 0))' at error location [2021-11-23 03:39:13,479 WARN L312 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2021-11-23 03:39:13,479 INFO L186 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2021-11-23 03:39:13,479 INFO L199 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [47, 47, 47] total 136 [2021-11-23 03:39:13,479 INFO L115 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1621277213] [2021-11-23 03:39:13,479 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2021-11-23 03:39:13,480 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 136 states [2021-11-23 03:39:13,480 INFO L103 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2021-11-23 03:39:13,480 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 136 interpolants. [2021-11-23 03:39:13,481 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=616, Invalid=20264, Unknown=0, NotChecked=0, Total=20880 [2021-11-23 03:39:13,482 INFO L87 Difference]: Start difference. First operand 70 states and 90 transitions. Second operand has 136 states, 136 states have (on average 1.0294117647058822) internal successors, (140), 136 states have internal predecessors, (140), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:39:51,477 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2021-11-23 03:39:51,478 INFO L93 Difference]: Finished difference Result 185 states and 210 transitions. [2021-11-23 03:39:51,478 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 121 states. [2021-11-23 03:39:51,478 INFO L78 Accepts]: Start accepts. Automaton has has 136 states, 136 states have (on average 1.0294117647058822) internal successors, (140), 136 states have internal predecessors, (140), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 48 [2021-11-23 03:39:51,478 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2021-11-23 03:39:51,480 INFO L225 Difference]: With dead ends: 185 [2021-11-23 03:39:51,480 INFO L226 Difference]: Without dead ends: 152 [2021-11-23 03:39:51,485 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 288 GetRequests, 45 SyntacticMatches, 1 SemanticMatches, 242 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 17607 ImplicationChecksByTransitivity, 48.0s TimeCoverageRelationStatistics Valid=2923, Invalid=56369, Unknown=0, NotChecked=0, Total=59292 [2021-11-23 03:39:51,486 INFO L933 BasicCegarLoop]: 4 mSDtfsCounter, 393 mSDsluCounter, 216 mSDsCounter, 0 mSdLazyCounter, 5214 mSolverCounterSat, 1337 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 3.9s Time, 0 mProtectedPredicate, 0 mProtectedAction, 393 SdHoareTripleChecker+Valid, 215 SdHoareTripleChecker+Invalid, 6551 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 1337 IncrementalHoareTripleChecker+Valid, 5214 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 4.5s IncrementalHoareTripleChecker+Time [2021-11-23 03:39:51,486 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [393 Valid, 215 Invalid, 6551 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [1337 Valid, 5214 Invalid, 0 Unknown, 0 Unchecked, 4.5s Time] [2021-11-23 03:39:51,487 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 152 states. [2021-11-23 03:39:51,828 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 152 to 94. [2021-11-23 03:39:51,828 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 94 states, 93 states have (on average 1.2473118279569892) internal successors, (116), 93 states have internal predecessors, (116), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:39:51,828 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 94 states to 94 states and 116 transitions. [2021-11-23 03:39:51,828 INFO L78 Accepts]: Start accepts. Automaton has 94 states and 116 transitions. Word has length 48 [2021-11-23 03:39:51,829 INFO L84 Accepts]: Finished accepts. word is rejected. [2021-11-23 03:39:51,829 INFO L470 AbstractCegarLoop]: Abstraction has 94 states and 116 transitions. [2021-11-23 03:39:51,829 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 136 states, 136 states have (on average 1.0294117647058822) internal successors, (140), 136 states have internal predecessors, (140), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:39:51,829 INFO L276 IsEmpty]: Start isEmpty. Operand 94 states and 116 transitions. [2021-11-23 03:39:51,829 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 51 [2021-11-23 03:39:51,829 INFO L506 BasicCegarLoop]: Found error trace [2021-11-23 03:39:51,830 INFO L514 BasicCegarLoop]: trace histogram [20, 20, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2021-11-23 03:39:51,856 INFO L540 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (26)] Forceful destruction successful, exit code 0 [2021-11-23 03:39:52,030 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: 26 /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true,SelfDestructingSolverStorable28 [2021-11-23 03:39:52,030 INFO L402 AbstractCegarLoop]: === Iteration 30 === Targeting ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION === [ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2021-11-23 03:39:52,031 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2021-11-23 03:39:52,031 INFO L85 PathProgramCache]: Analyzing trace with hash -446771790, now seen corresponding path program 24 times [2021-11-23 03:39:52,031 INFO L121 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2021-11-23 03:39:52,031 INFO L333 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [988045283] [2021-11-23 03:39:52,031 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:39:52,031 INFO L126 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2021-11-23 03:39:52,050 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:39:54,419 INFO L134 CoverageAnalysis]: Checked inductivity of 420 backedges. 0 proven. 420 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:39:54,420 INFO L139 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2021-11-23 03:39:54,420 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [988045283] [2021-11-23 03:39:54,420 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [988045283] provided 0 perfect and 1 imperfect interpolant sequences [2021-11-23 03:39:54,420 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1343455167] [2021-11-23 03:39:54,420 INFO L93 rtionOrderModulation]: Changing assertion order to TERMS_WITH_SMALL_CONSTANTS_FIRST [2021-11-23 03:39:54,420 INFO L168 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:39:54,421 INFO L189 MonitoredProcess]: No working directory specified, using /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 [2021-11-23 03:39:54,422 INFO L229 MonitoredProcess]: Starting monitored process 27 with /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2021-11-23 03:39:54,424 INFO L327 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (27)] Waiting until timeout for monitored process [2021-11-23 03:39:54,472 INFO L228 tOrderPrioritization]: Assert order TERMS_WITH_SMALL_CONSTANTS_FIRST issued 0 check-sat command(s) [2021-11-23 03:39:54,472 INFO L229 tOrderPrioritization]: Conjunction of SSA is unsat [2021-11-23 03:39:54,474 WARN L261 TraceCheckSpWp]: Trace formula consists of 196 conjuncts, 113 conjunts are in the unsatisfiable core [2021-11-23 03:39:54,476 INFO L286 TraceCheckSpWp]: Computing forward predicates... [2021-11-23 03:40:01,758 INFO L134 CoverageAnalysis]: Checked inductivity of 420 backedges. 0 proven. 420 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:40:01,758 INFO L328 TraceCheckSpWp]: Computing backward predicates... [2021-11-23 03:40:08,563 INFO L134 CoverageAnalysis]: Checked inductivity of 420 backedges. 0 proven. 420 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:40:08,564 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1343455167] provided 0 perfect and 2 imperfect interpolant sequences [2021-11-23 03:40:08,564 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [1360322674] [2021-11-23 03:40:08,566 INFO L159 IcfgInterpreter]: Started Sifa with 11 locations of interest [2021-11-23 03:40:08,566 INFO L166 IcfgInterpreter]: Building call graph [2021-11-23 03:40:08,566 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2021-11-23 03:40:08,567 INFO L176 IcfgInterpreter]: Starting interpretation [2021-11-23 03:40:08,567 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2021-11-23 03:40:08,723 INFO L180 IcfgInterpreter]: Interpretation finished [2021-11-23 03:40:11,190 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '15738#(and (<= 4 |ULTIMATE.start_correct_version_~i~0#1|) (<= |ULTIMATE.start_correct_version_#res#1| 1) (<= 4 |ULTIMATE.start_student_version_~w#1|) (<= |ULTIMATE.start_main_~is_divisible1~0#1| 1) (<= 4 |ULTIMATE.start_correct_version_~w#1|) (<= 4 |ULTIMATE.start_student_version_#in~w#1|) (<= 0 |ULTIMATE.start_correct_version_~is_divisible~0#1|) (= ~true~0 1) (<= |ULTIMATE.start_correct_version_~is_divisible~0#1| 1) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| 0) (<= 4 |ULTIMATE.start_correct_version_#in~w#1|) (= ~false~0 0) (<= 0 |ULTIMATE.start_correct_version_#res#1|) (or (and (not (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|)) (= |ULTIMATE.start_student_version_~is_divisible~1#1| ~false~0)) (and (<= 1 |ULTIMATE.start_student_version_~is_divisible~1#1|) (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (<= |ULTIMATE.start_student_version_~is_divisible~1#1| 1))) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (= |#NULL.offset| 0) (= (ite (= |ULTIMATE.start_main_~is_divisible1~0#1| |ULTIMATE.start_main_~is_divisible2~0#1|) 1 0) |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (<= 0 |ULTIMATE.start_main_~is_divisible1~0#1|) (= |ULTIMATE.start_student_version_~is_divisible~1#1| |ULTIMATE.start_student_version_#res#1|) (<= 0 |#StackHeapBarrier|) (= |ULTIMATE.start_main_~is_divisible2~0#1| |ULTIMATE.start_student_version_#res#1|) (<= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (= |#NULL.base| 0))' at error location [2021-11-23 03:40:11,190 WARN L312 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2021-11-23 03:40:11,190 INFO L186 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2021-11-23 03:40:11,191 INFO L199 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [49, 49, 49] total 141 [2021-11-23 03:40:11,191 INFO L115 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [332847598] [2021-11-23 03:40:11,191 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2021-11-23 03:40:11,193 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 141 states [2021-11-23 03:40:11,193 INFO L103 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2021-11-23 03:40:11,193 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 141 interpolants. [2021-11-23 03:40:11,195 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=640, Invalid=21710, Unknown=0, NotChecked=0, Total=22350 [2021-11-23 03:40:11,196 INFO L87 Difference]: Start difference. First operand 94 states and 116 transitions. Second operand has 141 states, 141 states have (on average 1.0283687943262412) internal successors, (145), 141 states have internal predecessors, (145), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:41:13,258 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2021-11-23 03:41:13,258 INFO L93 Difference]: Finished difference Result 212 states and 241 transitions. [2021-11-23 03:41:13,259 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 126 states. [2021-11-23 03:41:13,259 INFO L78 Accepts]: Start accepts. Automaton has has 141 states, 141 states have (on average 1.0283687943262412) internal successors, (145), 141 states have internal predecessors, (145), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 50 [2021-11-23 03:41:13,259 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2021-11-23 03:41:13,260 INFO L225 Difference]: With dead ends: 212 [2021-11-23 03:41:13,261 INFO L226 Difference]: Without dead ends: 178 [2021-11-23 03:41:13,266 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 300 GetRequests, 48 SyntacticMatches, 1 SemanticMatches, 251 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 18903 ImplicationChecksByTransitivity, 71.1s TimeCoverageRelationStatistics Valid=3090, Invalid=60666, Unknown=0, NotChecked=0, Total=63756 [2021-11-23 03:41:13,267 INFO L933 BasicCegarLoop]: 4 mSDtfsCounter, 410 mSDsluCounter, 298 mSDsCounter, 0 mSdLazyCounter, 6276 mSolverCounterSat, 1567 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 5.0s Time, 0 mProtectedPredicate, 0 mProtectedAction, 410 SdHoareTripleChecker+Valid, 295 SdHoareTripleChecker+Invalid, 7843 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 1567 IncrementalHoareTripleChecker+Valid, 6276 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 5.8s IncrementalHoareTripleChecker+Time [2021-11-23 03:41:13,268 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [410 Valid, 295 Invalid, 7843 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [1567 Valid, 6276 Invalid, 0 Unknown, 0 Unchecked, 5.8s Time] [2021-11-23 03:41:13,269 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 178 states. [2021-11-23 03:41:13,791 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 178 to 119. [2021-11-23 03:41:13,791 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 119 states, 118 states have (on average 1.2203389830508475) internal successors, (144), 118 states have internal predecessors, (144), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:41:13,792 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 119 states to 119 states and 144 transitions. [2021-11-23 03:41:13,792 INFO L78 Accepts]: Start accepts. Automaton has 119 states and 144 transitions. Word has length 50 [2021-11-23 03:41:13,792 INFO L84 Accepts]: Finished accepts. word is rejected. [2021-11-23 03:41:13,792 INFO L470 AbstractCegarLoop]: Abstraction has 119 states and 144 transitions. [2021-11-23 03:41:13,793 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 141 states, 141 states have (on average 1.0283687943262412) internal successors, (145), 141 states have internal predecessors, (145), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2021-11-23 03:41:13,793 INFO L276 IsEmpty]: Start isEmpty. Operand 119 states and 144 transitions. [2021-11-23 03:41:13,793 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 53 [2021-11-23 03:41:13,793 INFO L506 BasicCegarLoop]: Found error trace [2021-11-23 03:41:13,793 INFO L514 BasicCegarLoop]: trace histogram [21, 21, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2021-11-23 03:41:13,818 INFO L540 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (27)] Forceful destruction successful, exit code 0 [2021-11-23 03:41:13,994 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable29,27 /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:41:13,994 INFO L402 AbstractCegarLoop]: === Iteration 31 === Targeting ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION === [ULTIMATE.startErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2021-11-23 03:41:13,994 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2021-11-23 03:41:13,994 INFO L85 PathProgramCache]: Analyzing trace with hash 845092053, now seen corresponding path program 25 times [2021-11-23 03:41:13,994 INFO L121 FreeRefinementEngine]: Executing refinement strategy SIFA_TAIPAN [2021-11-23 03:41:13,995 INFO L333 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1761149802] [2021-11-23 03:41:13,995 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2021-11-23 03:41:13,995 INFO L126 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2021-11-23 03:41:14,014 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:41:16,602 INFO L134 CoverageAnalysis]: Checked inductivity of 462 backedges. 0 proven. 462 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:41:16,603 INFO L139 FreeRefinementEngine]: Strategy SIFA_TAIPAN found an infeasible trace [2021-11-23 03:41:16,603 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1761149802] [2021-11-23 03:41:16,603 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1761149802] provided 0 perfect and 1 imperfect interpolant sequences [2021-11-23 03:41:16,603 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1134505569] [2021-11-23 03:41:16,603 INFO L93 rtionOrderModulation]: Changing assertion order to NOT_INCREMENTALLY [2021-11-23 03:41:16,603 INFO L168 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2021-11-23 03:41:16,603 INFO L189 MonitoredProcess]: No working directory specified, using /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 [2021-11-23 03:41:16,604 INFO L229 MonitoredProcess]: Starting monitored process 28 with /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2021-11-23 03:41:16,605 INFO L327 MonitoredProcess]: [MP /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_0400a58c-74d9-420b-a921-f180a9d68299/bin/utaipan-EQgc7hIp5V/z3 -smt2 -in SMTLIB2_COMPLIANT=true (28)] Waiting until timeout for monitored process [2021-11-23 03:41:16,648 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2021-11-23 03:41:16,650 WARN L261 TraceCheckSpWp]: Trace formula consists of 202 conjuncts, 117 conjunts are in the unsatisfiable core [2021-11-23 03:41:16,652 INFO L286 TraceCheckSpWp]: Computing forward predicates... [2021-11-23 03:41:23,899 INFO L134 CoverageAnalysis]: Checked inductivity of 462 backedges. 0 proven. 462 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:41:23,900 INFO L328 TraceCheckSpWp]: Computing backward predicates... [2021-11-23 03:41:31,148 INFO L134 CoverageAnalysis]: Checked inductivity of 462 backedges. 0 proven. 462 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2021-11-23 03:41:31,148 INFO L160 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1134505569] provided 0 perfect and 2 imperfect interpolant sequences [2021-11-23 03:41:31,148 INFO L333 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSifa [1201054699] [2021-11-23 03:41:31,149 INFO L159 IcfgInterpreter]: Started Sifa with 11 locations of interest [2021-11-23 03:41:31,149 INFO L166 IcfgInterpreter]: Building call graph [2021-11-23 03:41:31,149 INFO L171 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2021-11-23 03:41:31,150 INFO L176 IcfgInterpreter]: Starting interpretation [2021-11-23 03:41:31,150 INFO L197 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 for LOIs [2021-11-23 03:41:31,329 INFO L180 IcfgInterpreter]: Interpretation finished [2021-11-23 03:41:34,127 INFO L133 SifaRunner]: Sifa could not show that error location is unreachable, found '17028#(and (<= 4 |ULTIMATE.start_correct_version_~i~0#1|) (<= |ULTIMATE.start_correct_version_#res#1| 1) (<= 4 |ULTIMATE.start_student_version_~w#1|) (<= |ULTIMATE.start_main_~is_divisible1~0#1| 1) (<= 4 |ULTIMATE.start_correct_version_~w#1|) (<= 4 |ULTIMATE.start_student_version_#in~w#1|) (<= 0 |ULTIMATE.start_correct_version_~is_divisible~0#1|) (<= |ULTIMATE.start_correct_version_~is_divisible~0#1| 1) (<= ~false~0 0) (<= |#NULL.offset| 0) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| 0) (<= 0 ~false~0) (<= 4 |ULTIMATE.start_correct_version_#in~w#1|) (<= 1 ~true~0) (<= 0 |ULTIMATE.start_correct_version_#res#1|) (or (and (not (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|)) (= |ULTIMATE.start_student_version_~is_divisible~1#1| ~false~0)) (and (<= 1 |ULTIMATE.start_student_version_~is_divisible~1#1|) (= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (<= |ULTIMATE.start_student_version_~is_divisible~1#1| 1))) (= |ULTIMATE.start___VERIFIER_assert_~cond#1| |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (= (ite (= |ULTIMATE.start_main_~is_divisible1~0#1| |ULTIMATE.start_main_~is_divisible2~0#1|) 1 0) |ULTIMATE.start___VERIFIER_assert_#in~cond#1|) (<= 0 |ULTIMATE.start_main_~is_divisible1~0#1|) (<= ~true~0 1) (= |ULTIMATE.start_student_version_~is_divisible~1#1| |ULTIMATE.start_student_version_#res#1|) (<= 0 |#NULL.offset|) (<= 0 |#StackHeapBarrier|) (= |ULTIMATE.start_main_~is_divisible2~0#1| |ULTIMATE.start_student_version_#res#1|) (<= |ULTIMATE.start_student_version_~w#1| |ULTIMATE.start_student_version_~i~1#1|) (= |#NULL.base| 0))' at error location [2021-11-23 03:41:34,127 WARN L312 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: ALGORITHM_FAILED [2021-11-23 03:41:34,128 INFO L186 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2021-11-23 03:41:34,128 INFO L199 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [51, 51, 51] total 147 [2021-11-23 03:41:34,128 INFO L115 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1783403224] [2021-11-23 03:41:34,128 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2021-11-23 03:41:34,128 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 147 states [2021-11-23 03:41:34,129 INFO L103 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy SIFA_TAIPAN [2021-11-23 03:41:34,129 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 147 interpolants. [2021-11-23 03:41:34,130 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=667, Invalid=23513, Unknown=0, NotChecked=0, Total=24180 [2021-11-23 03:41:34,131 INFO L87 Difference]: Start difference. First operand 119 states and 144 transitions. Second operand has 147 states, 147 states have (on average 1.0272108843537415) internal successors, (151), 147 states have internal predecessors, (151), 0 states have call successors, (0), 0 states have call predecessors, (0), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0)