/usr/bin/java -Xmx8000000000 -Xss4m -jar ./plugins/org.eclipse.equinox.launcher_1.5.800.v20200727-1323.jar -data @noDefault -ultimatedata ./data --core.log.level.for.class de.uni_freiburg.informatik.ultimate.lib.smtlibutils.quantifier.QuantifierPusher=WARN -tc ../../../trunk/examples/toolchains/AutomizerCTransformed.xml -s ../../../trunk/examples/settings/automizer/LoopAccelerationJordanC.epf -i ../../../trunk/examples/svcomp/loop-invgen/nested6.i -------------------------------------------------------------------------------- This is Ultimate 0.2.2-dev-6c470ae [2022-02-14 20:51:00,418 INFO L177 SettingsManager]: Resetting all preferences to default values... [2022-02-14 20:51:00,420 INFO L181 SettingsManager]: Resetting UltimateCore preferences to default values [2022-02-14 20:51:00,499 INFO L184 SettingsManager]: Ultimate Commandline Interface provides no preferences, ignoring... [2022-02-14 20:51:00,499 INFO L181 SettingsManager]: Resetting Boogie Preprocessor preferences to default values [2022-02-14 20:51:00,502 INFO L181 SettingsManager]: Resetting Boogie Procedure Inliner preferences to default values [2022-02-14 20:51:00,504 INFO L181 SettingsManager]: Resetting Abstract Interpretation preferences to default values [2022-02-14 20:51:00,505 INFO L181 SettingsManager]: Resetting LassoRanker preferences to default values [2022-02-14 20:51:00,507 INFO L181 SettingsManager]: Resetting Reaching Definitions preferences to default values [2022-02-14 20:51:00,510 INFO L181 SettingsManager]: Resetting SyntaxChecker preferences to default values [2022-02-14 20:51:00,511 INFO L181 SettingsManager]: Resetting Sifa preferences to default values [2022-02-14 20:51:00,513 INFO L184 SettingsManager]: Büchi Program Product provides no preferences, ignoring... [2022-02-14 20:51:00,513 INFO L181 SettingsManager]: Resetting LTL2Aut preferences to default values [2022-02-14 20:51:00,515 INFO L181 SettingsManager]: Resetting PEA to Boogie preferences to default values [2022-02-14 20:51:00,516 INFO L181 SettingsManager]: Resetting BlockEncodingV2 preferences to default values [2022-02-14 20:51:00,518 INFO L181 SettingsManager]: Resetting ChcToBoogie preferences to default values [2022-02-14 20:51:00,519 INFO L181 SettingsManager]: Resetting AutomataScriptInterpreter preferences to default values [2022-02-14 20:51:00,520 INFO L181 SettingsManager]: Resetting BuchiAutomizer preferences to default values [2022-02-14 20:51:00,522 INFO L181 SettingsManager]: Resetting CACSL2BoogieTranslator preferences to default values [2022-02-14 20:51:00,526 INFO L181 SettingsManager]: Resetting CodeCheck preferences to default values [2022-02-14 20:51:00,527 INFO L181 SettingsManager]: Resetting InvariantSynthesis preferences to default values [2022-02-14 20:51:00,528 INFO L181 SettingsManager]: Resetting RCFGBuilder preferences to default values [2022-02-14 20:51:00,530 INFO L181 SettingsManager]: Resetting Referee preferences to default values [2022-02-14 20:51:00,531 INFO L181 SettingsManager]: Resetting TraceAbstraction preferences to default values [2022-02-14 20:51:00,536 INFO L184 SettingsManager]: TraceAbstractionConcurrent provides no preferences, ignoring... [2022-02-14 20:51:00,536 INFO L184 SettingsManager]: TraceAbstractionWithAFAs provides no preferences, ignoring... [2022-02-14 20:51:00,537 INFO L181 SettingsManager]: Resetting TreeAutomizer preferences to default values [2022-02-14 20:51:00,538 INFO L181 SettingsManager]: Resetting IcfgToChc preferences to default values [2022-02-14 20:51:00,538 INFO L181 SettingsManager]: Resetting IcfgTransformer preferences to default values [2022-02-14 20:51:00,539 INFO L184 SettingsManager]: ReqToTest provides no preferences, ignoring... [2022-02-14 20:51:00,539 INFO L181 SettingsManager]: Resetting Boogie Printer preferences to default values [2022-02-14 20:51:00,540 INFO L181 SettingsManager]: Resetting ChcSmtPrinter preferences to default values [2022-02-14 20:51:00,541 INFO L181 SettingsManager]: Resetting ReqPrinter preferences to default values [2022-02-14 20:51:00,541 INFO L181 SettingsManager]: Resetting Witness Printer preferences to default values [2022-02-14 20:51:00,543 INFO L184 SettingsManager]: Boogie PL CUP Parser provides no preferences, ignoring... [2022-02-14 20:51:00,543 INFO L181 SettingsManager]: Resetting CDTParser preferences to default values [2022-02-14 20:51:00,543 INFO L184 SettingsManager]: AutomataScriptParser provides no preferences, ignoring... [2022-02-14 20:51:00,543 INFO L184 SettingsManager]: ReqParser provides no preferences, ignoring... [2022-02-14 20:51:00,544 INFO L181 SettingsManager]: Resetting SmtParser preferences to default values [2022-02-14 20:51:00,544 INFO L181 SettingsManager]: Resetting Witness Parser preferences to default values [2022-02-14 20:51:00,545 INFO L188 SettingsManager]: Finished resetting all preferences to default values... [2022-02-14 20:51:00,545 INFO L101 SettingsManager]: Beginning loading settings from /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/../../../trunk/examples/settings/automizer/LoopAccelerationJordanC.epf [2022-02-14 20:51:00,556 INFO L113 SettingsManager]: Loading preferences was successful [2022-02-14 20:51:00,556 INFO L115 SettingsManager]: Preferences different from defaults after loading the file: [2022-02-14 20:51:00,557 INFO L136 SettingsManager]: Preferences of CACSL2BoogieTranslator differ from their defaults: [2022-02-14 20:51:00,558 INFO L138 SettingsManager]: * sizeof long=4 [2022-02-14 20:51:00,558 INFO L138 SettingsManager]: * Overapproximate operations on floating types=true [2022-02-14 20:51:00,558 INFO L138 SettingsManager]: * sizeof POINTER=4 [2022-02-14 20:51:00,558 INFO L138 SettingsManager]: * Check division by zero=IGNORE [2022-02-14 20:51:00,558 INFO L138 SettingsManager]: * Pointer to allocated memory at dereference=IGNORE [2022-02-14 20:51:00,558 INFO L138 SettingsManager]: * If two pointers are subtracted or compared they have the same base address=IGNORE [2022-02-14 20:51:00,558 INFO L138 SettingsManager]: * Check array bounds for arrays that are off heap=IGNORE [2022-02-14 20:51:00,559 INFO L138 SettingsManager]: * sizeof long double=12 [2022-02-14 20:51:00,559 INFO L138 SettingsManager]: * Check if freed pointer was valid=false [2022-02-14 20:51:00,559 INFO L138 SettingsManager]: * Use constant arrays=true [2022-02-14 20:51:00,559 INFO L138 SettingsManager]: * Pointer base address is valid at dereference=IGNORE [2022-02-14 20:51:00,559 INFO L136 SettingsManager]: Preferences of RCFGBuilder differ from their defaults: [2022-02-14 20:51:00,560 INFO L138 SettingsManager]: * Size of a code block=SequenceOfStatements [2022-02-14 20:51:00,560 INFO L138 SettingsManager]: * To the following directory=./dump/ [2022-02-14 20:51:00,560 INFO L138 SettingsManager]: * SMT solver=External_DefaultMode [2022-02-14 20:51:00,560 INFO L138 SettingsManager]: * Command for external solver=z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in -t:2000 [2022-02-14 20:51:00,560 INFO L136 SettingsManager]: Preferences of TraceAbstraction differ from their defaults: [2022-02-14 20:51:00,560 INFO L138 SettingsManager]: * Trace refinement strategy=CAMEL [2022-02-14 20:51:00,561 INFO L136 SettingsManager]: Preferences of IcfgTransformer differ from their defaults: [2022-02-14 20:51:00,561 INFO L138 SettingsManager]: * TransformationType=LOOP_ACCELERATION_JORDAN WARNING: An illegal reflective access operation has occurred WARNING: Illegal reflective access by com.sun.xml.bind.v2.runtime.reflect.opt.Injector$1 (file:/storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/plugins/com.sun.xml.bind_2.2.0.v201505121915.jar) to method java.lang.ClassLoader.defineClass(java.lang.String,byte[],int,int) WARNING: Please consider reporting this to the maintainers of com.sun.xml.bind.v2.runtime.reflect.opt.Injector$1 WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations WARNING: All illegal access operations will be denied in a future release Applying setting for plugin de.uni_freiburg.informatik.ultimate.core: Log level for class -> de.uni_freiburg.informatik.ultimate.lib.smtlibutils.quantifier.QuantifierPusher=WARN; [2022-02-14 20:51:00,783 INFO L75 nceAwareModelManager]: Repository-Root is: /tmp [2022-02-14 20:51:00,807 INFO L261 ainManager$Toolchain]: [Toolchain 1]: Applicable parser(s) successfully (re)initialized [2022-02-14 20:51:00,809 INFO L217 ainManager$Toolchain]: [Toolchain 1]: Toolchain selected. [2022-02-14 20:51:00,810 INFO L271 PluginConnector]: Initializing CDTParser... [2022-02-14 20:51:00,810 INFO L275 PluginConnector]: CDTParser initialized [2022-02-14 20:51:00,811 INFO L432 ainManager$Toolchain]: [Toolchain 1]: Parsing single file: /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/../../../trunk/examples/svcomp/loop-invgen/nested6.i [2022-02-14 20:51:00,873 INFO L220 CDTParser]: Created temporary CDT project at /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/data/56e1121ff/339a9a4413bb49178077da3b4984ff5a/FLAGf54bf7505 [2022-02-14 20:51:01,228 INFO L306 CDTParser]: Found 1 translation units. [2022-02-14 20:51:01,228 INFO L160 CDTParser]: Scanning /storage/repos/ultimate/trunk/examples/svcomp/loop-invgen/nested6.i [2022-02-14 20:51:01,239 INFO L349 CDTParser]: About to delete temporary CDT project at /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/data/56e1121ff/339a9a4413bb49178077da3b4984ff5a/FLAGf54bf7505 [2022-02-14 20:51:01,248 INFO L357 CDTParser]: Successfully deleted /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/data/56e1121ff/339a9a4413bb49178077da3b4984ff5a [2022-02-14 20:51:01,250 INFO L299 ainManager$Toolchain]: ####################### [Toolchain 1] ####################### [2022-02-14 20:51:01,251 INFO L131 ToolchainWalker]: Walking toolchain with 5 elements. [2022-02-14 20:51:01,255 INFO L113 PluginConnector]: ------------------------CACSL2BoogieTranslator---------------------------- [2022-02-14 20:51:01,255 INFO L271 PluginConnector]: Initializing CACSL2BoogieTranslator... [2022-02-14 20:51:01,258 INFO L275 PluginConnector]: CACSL2BoogieTranslator initialized [2022-02-14 20:51:01,258 INFO L185 PluginConnector]: Executing the observer ACSLObjectContainerObserver from plugin CACSL2BoogieTranslator for "CDTParser AST 14.02 08:51:01" (1/1) ... [2022-02-14 20:51:01,259 INFO L205 PluginConnector]: Invalid model from CACSL2BoogieTranslator for observer de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator.ACSLObjectContainerObserver@4f7162a9 and model type de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 14.02 08:51:01, skipping insertion in model container [2022-02-14 20:51:01,260 INFO L185 PluginConnector]: Executing the observer CACSL2BoogieTranslatorObserver from plugin CACSL2BoogieTranslator for "CDTParser AST 14.02 08:51:01" (1/1) ... [2022-02-14 20:51:01,264 INFO L145 MainTranslator]: Starting translation in SV-COMP mode [2022-02-14 20:51:01,276 INFO L178 MainTranslator]: Built tables and reachable declarations [2022-02-14 20:51:01,392 WARN L230 ndardFunctionHandler]: Function reach_error is already implemented but we override the implementation for the call at /storage/repos/ultimate/trunk/examples/svcomp/loop-invgen/nested6.i[893,906] [2022-02-14 20:51:01,417 INFO L210 PostProcessor]: Analyzing one entry point: main [2022-02-14 20:51:01,423 INFO L203 MainTranslator]: Completed pre-run [2022-02-14 20:51:01,433 WARN L230 ndardFunctionHandler]: Function reach_error is already implemented but we override the implementation for the call at /storage/repos/ultimate/trunk/examples/svcomp/loop-invgen/nested6.i[893,906] [2022-02-14 20:51:01,440 INFO L210 PostProcessor]: Analyzing one entry point: main [2022-02-14 20:51:01,449 INFO L208 MainTranslator]: Completed translation [2022-02-14 20:51:01,450 INFO L202 PluginConnector]: Adding new model de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 14.02 08:51:01 WrapperNode [2022-02-14 20:51:01,450 INFO L132 PluginConnector]: ------------------------ END CACSL2BoogieTranslator---------------------------- [2022-02-14 20:51:01,451 INFO L113 PluginConnector]: ------------------------Boogie Preprocessor---------------------------- [2022-02-14 20:51:01,451 INFO L271 PluginConnector]: Initializing Boogie Preprocessor... [2022-02-14 20:51:01,451 INFO L275 PluginConnector]: Boogie Preprocessor initialized [2022-02-14 20:51:01,459 INFO L185 PluginConnector]: Executing the observer EnsureBoogieModelObserver from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 14.02 08:51:01" (1/1) ... [2022-02-14 20:51:01,460 INFO L185 PluginConnector]: Executing the observer TypeChecker from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 14.02 08:51:01" (1/1) ... [2022-02-14 20:51:01,464 INFO L185 PluginConnector]: Executing the observer ConstExpander from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 14.02 08:51:01" (1/1) ... [2022-02-14 20:51:01,465 INFO L185 PluginConnector]: Executing the observer StructExpander from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 14.02 08:51:01" (1/1) ... [2022-02-14 20:51:01,468 INFO L185 PluginConnector]: Executing the observer UnstructureCode from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 14.02 08:51:01" (1/1) ... [2022-02-14 20:51:01,471 INFO L185 PluginConnector]: Executing the observer FunctionInliner from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 14.02 08:51:01" (1/1) ... [2022-02-14 20:51:01,472 INFO L185 PluginConnector]: Executing the observer BoogieSymbolTableConstructor from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 14.02 08:51:01" (1/1) ... [2022-02-14 20:51:01,473 INFO L132 PluginConnector]: ------------------------ END Boogie Preprocessor---------------------------- [2022-02-14 20:51:01,474 INFO L113 PluginConnector]: ------------------------RCFGBuilder---------------------------- [2022-02-14 20:51:01,474 INFO L271 PluginConnector]: Initializing RCFGBuilder... [2022-02-14 20:51:01,474 INFO L275 PluginConnector]: RCFGBuilder initialized [2022-02-14 20:51:01,475 INFO L185 PluginConnector]: Executing the observer RCFGBuilderObserver from plugin RCFGBuilder for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 14.02 08:51:01" (1/1) ... [2022-02-14 20:51:01,481 INFO L173 SolverBuilder]: Constructing external solver with command: z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in -t:2000 [2022-02-14 20:51:01,497 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2022-02-14 20:51:01,516 INFO L229 MonitoredProcess]: Starting monitored process 1 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in -t:2000 (exit command is (exit), workingDir is null) [2022-02-14 20:51:01,537 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in -t:2000 (1)] Waiting until timeout for monitored process [2022-02-14 20:51:01,559 INFO L138 BoogieDeclarations]: Found implementation of procedure ULTIMATE.init [2022-02-14 20:51:01,559 INFO L138 BoogieDeclarations]: Found implementation of procedure ULTIMATE.start [2022-02-14 20:51:01,559 INFO L138 BoogieDeclarations]: Found implementation of procedure reach_error [2022-02-14 20:51:01,559 INFO L138 BoogieDeclarations]: Found implementation of procedure assume_abort_if_not [2022-02-14 20:51:01,560 INFO L138 BoogieDeclarations]: Found implementation of procedure __VERIFIER_assert [2022-02-14 20:51:01,560 INFO L138 BoogieDeclarations]: Found implementation of procedure main [2022-02-14 20:51:01,561 INFO L130 BoogieDeclarations]: Found specification of procedure abort [2022-02-14 20:51:01,561 INFO L130 BoogieDeclarations]: Found specification of procedure __assert_fail [2022-02-14 20:51:01,561 INFO L130 BoogieDeclarations]: Found specification of procedure __assert_perror_fail [2022-02-14 20:51:01,561 INFO L130 BoogieDeclarations]: Found specification of procedure __assert [2022-02-14 20:51:01,561 INFO L130 BoogieDeclarations]: Found specification of procedure reach_error [2022-02-14 20:51:01,561 INFO L130 BoogieDeclarations]: Found specification of procedure #Ultimate.allocInit [2022-02-14 20:51:01,562 INFO L130 BoogieDeclarations]: Found specification of procedure assume_abort_if_not [2022-02-14 20:51:01,562 INFO L130 BoogieDeclarations]: Found specification of procedure __VERIFIER_assert [2022-02-14 20:51:01,562 INFO L130 BoogieDeclarations]: Found specification of procedure __VERIFIER_nondet_int [2022-02-14 20:51:01,563 INFO L130 BoogieDeclarations]: Found specification of procedure main [2022-02-14 20:51:01,565 INFO L130 BoogieDeclarations]: Found specification of procedure ULTIMATE.init [2022-02-14 20:51:01,565 INFO L130 BoogieDeclarations]: Found specification of procedure write~init~int [2022-02-14 20:51:01,565 INFO L130 BoogieDeclarations]: Found specification of procedure ULTIMATE.start [2022-02-14 20:51:01,565 INFO L130 BoogieDeclarations]: Found specification of procedure write~int [2022-02-14 20:51:01,565 INFO L130 BoogieDeclarations]: Found specification of procedure read~int [2022-02-14 20:51:01,565 INFO L130 BoogieDeclarations]: Found specification of procedure ULTIMATE.dealloc [2022-02-14 20:51:01,645 INFO L234 CfgBuilder]: Building ICFG [2022-02-14 20:51:01,646 INFO L260 CfgBuilder]: Building CFG for each procedure with an implementation [2022-02-14 20:51:01,743 INFO L275 CfgBuilder]: Performing block encoding [2022-02-14 20:51:01,748 INFO L294 CfgBuilder]: Using the 1 location(s) as analysis (start of procedure ULTIMATE.start) [2022-02-14 20:51:01,749 INFO L299 CfgBuilder]: Removed 3 assume(true) statements. [2022-02-14 20:51:01,750 INFO L202 PluginConnector]: Adding new model de.uni_freiburg.informatik.ultimate.plugins.generator.rcfgbuilder CFG 14.02 08:51:01 BoogieIcfgContainer [2022-02-14 20:51:01,750 INFO L132 PluginConnector]: ------------------------ END RCFGBuilder---------------------------- [2022-02-14 20:51:01,751 INFO L113 PluginConnector]: ------------------------IcfgTransformer---------------------------- [2022-02-14 20:51:01,751 INFO L271 PluginConnector]: Initializing IcfgTransformer... [2022-02-14 20:51:01,752 INFO L275 PluginConnector]: IcfgTransformer initialized [2022-02-14 20:51:01,755 INFO L185 PluginConnector]: Executing the observer IcfgTransformationObserver from plugin IcfgTransformer for "de.uni_freiburg.informatik.ultimate.plugins.generator.rcfgbuilder CFG 14.02 08:51:01" (1/1) ... [2022-02-14 20:51:01,768 INFO L202 PluginConnector]: Adding new model de.uni_freiburg.informatik.ultimate.plugins.icfgtransformation CFG 14.02 08:51:01 BasicIcfg [2022-02-14 20:51:01,768 INFO L132 PluginConnector]: ------------------------ END IcfgTransformer---------------------------- [2022-02-14 20:51:01,770 INFO L113 PluginConnector]: ------------------------TraceAbstraction---------------------------- [2022-02-14 20:51:01,770 INFO L271 PluginConnector]: Initializing TraceAbstraction... [2022-02-14 20:51:01,772 INFO L275 PluginConnector]: TraceAbstraction initialized [2022-02-14 20:51:01,772 INFO L185 PluginConnector]: Executing the observer TraceAbstractionObserver from plugin TraceAbstraction for "CDTParser AST 14.02 08:51:01" (1/4) ... [2022-02-14 20:51:01,773 INFO L205 PluginConnector]: Invalid model from TraceAbstraction for observer de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction.TraceAbstractionObserver@551a5d4d and model type de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction AST 14.02 08:51:01, skipping insertion in model container [2022-02-14 20:51:01,773 INFO L185 PluginConnector]: Executing the observer TraceAbstractionObserver from plugin TraceAbstraction for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 14.02 08:51:01" (2/4) ... [2022-02-14 20:51:01,773 INFO L205 PluginConnector]: Invalid model from TraceAbstraction for observer de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction.TraceAbstractionObserver@551a5d4d and model type de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction AST 14.02 08:51:01, skipping insertion in model container [2022-02-14 20:51:01,773 INFO L185 PluginConnector]: Executing the observer TraceAbstractionObserver from plugin TraceAbstraction for "de.uni_freiburg.informatik.ultimate.plugins.generator.rcfgbuilder CFG 14.02 08:51:01" (3/4) ... [2022-02-14 20:51:01,774 INFO L205 PluginConnector]: Invalid model from TraceAbstraction for observer de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction.TraceAbstractionObserver@551a5d4d and model type de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction CFG 14.02 08:51:01, skipping insertion in model container [2022-02-14 20:51:01,774 INFO L185 PluginConnector]: Executing the observer TraceAbstractionObserver from plugin TraceAbstraction for "de.uni_freiburg.informatik.ultimate.plugins.icfgtransformation CFG 14.02 08:51:01" (4/4) ... [2022-02-14 20:51:01,775 INFO L111 eAbstractionObserver]: Analyzing ICFG nested6.iJordan [2022-02-14 20:51:01,779 INFO L205 ceAbstractionStarter]: Automizer settings: Hoare:false NWA Interpolation:ForwardPredicates Determinization: PREDICATE_ABSTRACTION [2022-02-14 20:51:01,779 INFO L164 ceAbstractionStarter]: Applying trace abstraction to program that has 1 error locations. [2022-02-14 20:51:01,812 INFO L338 AbstractCegarLoop]: ======== Iteration 0 == of CEGAR loop == AllErrorsAtOnce ======== [2022-02-14 20:51:01,817 INFO L339 AbstractCegarLoop]: Settings: SEPARATE_VIOLATION_CHECK=true, mInterprocedural=true, mMaxIterations=1000000, mWatchIteration=1000000, mArtifact=RCFG, mInterpolation=ForwardPredicates, mInterpolantAutomaton=STRAIGHT_LINE, mDumpAutomata=false, mAutomataFormat=ATS_NUMERATE, mDumpPath=., mDeterminiation=PREDICATE_ABSTRACTION, mMinimize=MINIMIZE_SEVPA, mHoare=false, mAutomataTypeConcurrency=FINITE_AUTOMATA, mHoareTripleChecks=INCREMENTAL, mHoareAnnotationPositions=All, 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 [2022-02-14 20:51:01,818 INFO L340 AbstractCegarLoop]: Starting to check reachability of 1 error locations. [2022-02-14 20:51:01,828 INFO L276 IsEmpty]: Start isEmpty. Operand has 30 states, 20 states have (on average 1.55) internal successors, (31), 22 states have internal predecessors, (31), 5 states have call successors, (5), 3 states have call predecessors, (5), 3 states have return successors, (5), 5 states have call predecessors, (5), 5 states have call successors, (5) [2022-02-14 20:51:01,834 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 17 [2022-02-14 20:51:01,834 INFO L506 BasicCegarLoop]: Found error trace [2022-02-14 20:51:01,835 INFO L514 BasicCegarLoop]: trace histogram [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2022-02-14 20:51:01,835 INFO L402 AbstractCegarLoop]: === Iteration 1 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2022-02-14 20:51:01,839 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2022-02-14 20:51:01,840 INFO L85 PathProgramCache]: Analyzing trace with hash -1002152396, now seen corresponding path program 1 times [2022-02-14 20:51:01,846 INFO L126 FreeRefinementEngine]: Executing refinement strategy CAMEL [2022-02-14 20:51:01,847 INFO L338 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [13388872] [2022-02-14 20:51:01,847 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2022-02-14 20:51:01,847 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2022-02-14 20:51:01,942 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:02,066 INFO L376 atingTraceCheckCraig]: Compute interpolants for subsequence at non-pending call position 0 [2022-02-14 20:51:02,070 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:02,077 INFO L134 CoverageAnalysis]: Checked inductivity of 0 backedges. 0 proven. 0 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2022-02-14 20:51:02,078 INFO L144 FreeRefinementEngine]: Strategy CAMEL found an infeasible trace [2022-02-14 20:51:02,078 INFO L338 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [13388872] [2022-02-14 20:51:02,079 INFO L165 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [13388872] provided 1 perfect and 0 imperfect interpolant sequences [2022-02-14 20:51:02,079 INFO L191 FreeRefinementEngine]: Found 1 perfect and 0 imperfect interpolant sequences. [2022-02-14 20:51:02,079 INFO L204 FreeRefinementEngine]: Number of different interpolants: perfect sequences [6] imperfect sequences [] total 6 [2022-02-14 20:51:02,081 INFO L118 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1261674796] [2022-02-14 20:51:02,081 INFO L85 oduleStraightlineAll]: Using 1 perfect interpolants to construct interpolant automaton [2022-02-14 20:51:02,085 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 6 states [2022-02-14 20:51:02,085 INFO L108 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy CAMEL [2022-02-14 20:51:02,106 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 6 interpolants. [2022-02-14 20:51:02,107 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=9, Invalid=21, Unknown=0, NotChecked=0, Total=30 [2022-02-14 20:51:02,109 INFO L87 Difference]: Start difference. First operand has 30 states, 20 states have (on average 1.55) internal successors, (31), 22 states have internal predecessors, (31), 5 states have call successors, (5), 3 states have call predecessors, (5), 3 states have return successors, (5), 5 states have call predecessors, (5), 5 states have call successors, (5) Second operand has 6 states, 6 states have (on average 2.0) internal successors, (12), 4 states have internal predecessors, (12), 2 states have call successors, (3), 3 states have call predecessors, (3), 1 states have return successors, (1), 1 states have call predecessors, (1), 1 states have call successors, (1) [2022-02-14 20:51:02,245 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2022-02-14 20:51:02,246 INFO L93 Difference]: Finished difference Result 37 states and 43 transitions. [2022-02-14 20:51:02,247 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 7 states. [2022-02-14 20:51:02,248 INFO L78 Accepts]: Start accepts. Automaton has has 6 states, 6 states have (on average 2.0) internal successors, (12), 4 states have internal predecessors, (12), 2 states have call successors, (3), 3 states have call predecessors, (3), 1 states have return successors, (1), 1 states have call predecessors, (1), 1 states have call successors, (1) Word has length 16 [2022-02-14 20:51:02,248 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2022-02-14 20:51:02,254 INFO L225 Difference]: With dead ends: 37 [2022-02-14 20:51:02,254 INFO L226 Difference]: Without dead ends: 29 [2022-02-14 20:51:02,255 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 12 GetRequests, 4 SyntacticMatches, 0 SemanticMatches, 8 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 5 ImplicationChecksByTransitivity, 0.0s TimeCoverageRelationStatistics Valid=28, Invalid=62, Unknown=0, NotChecked=0, Total=90 [2022-02-14 20:51:02,258 INFO L933 BasicCegarLoop]: 31 mSDtfsCounter, 39 mSDsluCounter, 21 mSDsCounter, 0 mSdLazyCounter, 97 mSolverCounterSat, 10 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.1s Time, 0 mProtectedPredicate, 0 mProtectedAction, 40 SdHoareTripleChecker+Valid, 52 SdHoareTripleChecker+Invalid, 107 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 10 IncrementalHoareTripleChecker+Valid, 97 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.1s IncrementalHoareTripleChecker+Time [2022-02-14 20:51:02,264 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [40 Valid, 52 Invalid, 107 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [10 Valid, 97 Invalid, 0 Unknown, 0 Unchecked, 0.1s Time] [2022-02-14 20:51:02,280 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 29 states. [2022-02-14 20:51:02,304 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 29 to 29. [2022-02-14 20:51:02,305 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 29 states, 20 states have (on average 1.2) internal successors, (24), 21 states have internal predecessors, (24), 5 states have call successors, (5), 4 states have call predecessors, (5), 3 states have return successors, (4), 4 states have call predecessors, (4), 4 states have call successors, (4) [2022-02-14 20:51:02,306 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 29 states to 29 states and 33 transitions. [2022-02-14 20:51:02,307 INFO L78 Accepts]: Start accepts. Automaton has 29 states and 33 transitions. Word has length 16 [2022-02-14 20:51:02,307 INFO L84 Accepts]: Finished accepts. word is rejected. [2022-02-14 20:51:02,307 INFO L470 AbstractCegarLoop]: Abstraction has 29 states and 33 transitions. [2022-02-14 20:51:02,308 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 6 states, 6 states have (on average 2.0) internal successors, (12), 4 states have internal predecessors, (12), 2 states have call successors, (3), 3 states have call predecessors, (3), 1 states have return successors, (1), 1 states have call predecessors, (1), 1 states have call successors, (1) [2022-02-14 20:51:02,308 INFO L276 IsEmpty]: Start isEmpty. Operand 29 states and 33 transitions. [2022-02-14 20:51:02,308 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 18 [2022-02-14 20:51:02,308 INFO L506 BasicCegarLoop]: Found error trace [2022-02-14 20:51:02,309 INFO L514 BasicCegarLoop]: trace histogram [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2022-02-14 20:51:02,309 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable0 [2022-02-14 20:51:02,309 INFO L402 AbstractCegarLoop]: === Iteration 2 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2022-02-14 20:51:02,310 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2022-02-14 20:51:02,310 INFO L85 PathProgramCache]: Analyzing trace with hash -1031567308, now seen corresponding path program 1 times [2022-02-14 20:51:02,310 INFO L126 FreeRefinementEngine]: Executing refinement strategy CAMEL [2022-02-14 20:51:02,311 INFO L338 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1612896407] [2022-02-14 20:51:02,311 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2022-02-14 20:51:02,313 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2022-02-14 20:51:02,329 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:02,398 INFO L376 atingTraceCheckCraig]: Compute interpolants for subsequence at non-pending call position 0 [2022-02-14 20:51:02,401 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:02,410 INFO L134 CoverageAnalysis]: Checked inductivity of 0 backedges. 0 proven. 0 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2022-02-14 20:51:02,411 INFO L144 FreeRefinementEngine]: Strategy CAMEL found an infeasible trace [2022-02-14 20:51:02,411 INFO L338 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1612896407] [2022-02-14 20:51:02,411 INFO L165 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1612896407] provided 1 perfect and 0 imperfect interpolant sequences [2022-02-14 20:51:02,411 INFO L191 FreeRefinementEngine]: Found 1 perfect and 0 imperfect interpolant sequences. [2022-02-14 20:51:02,411 INFO L204 FreeRefinementEngine]: Number of different interpolants: perfect sequences [7] imperfect sequences [] total 7 [2022-02-14 20:51:02,412 INFO L118 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [962320622] [2022-02-14 20:51:02,412 INFO L85 oduleStraightlineAll]: Using 1 perfect interpolants to construct interpolant automaton [2022-02-14 20:51:02,413 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 7 states [2022-02-14 20:51:02,413 INFO L108 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy CAMEL [2022-02-14 20:51:02,414 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 7 interpolants. [2022-02-14 20:51:02,414 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=11, Invalid=31, Unknown=0, NotChecked=0, Total=42 [2022-02-14 20:51:02,414 INFO L87 Difference]: Start difference. First operand 29 states and 33 transitions. Second operand has 7 states, 7 states have (on average 1.8571428571428572) internal successors, (13), 5 states have internal predecessors, (13), 2 states have call successors, (3), 3 states have call predecessors, (3), 1 states have return successors, (1), 1 states have call predecessors, (1), 1 states have call successors, (1) [2022-02-14 20:51:02,594 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2022-02-14 20:51:02,594 INFO L93 Difference]: Finished difference Result 39 states and 46 transitions. [2022-02-14 20:51:02,594 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 8 states. [2022-02-14 20:51:02,595 INFO L78 Accepts]: Start accepts. Automaton has has 7 states, 7 states have (on average 1.8571428571428572) internal successors, (13), 5 states have internal predecessors, (13), 2 states have call successors, (3), 3 states have call predecessors, (3), 1 states have return successors, (1), 1 states have call predecessors, (1), 1 states have call successors, (1) Word has length 17 [2022-02-14 20:51:02,596 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2022-02-14 20:51:02,597 INFO L225 Difference]: With dead ends: 39 [2022-02-14 20:51:02,597 INFO L226 Difference]: Without dead ends: 39 [2022-02-14 20:51:02,603 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 13 GetRequests, 3 SyntacticMatches, 0 SemanticMatches, 10 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 8 ImplicationChecksByTransitivity, 0.1s TimeCoverageRelationStatistics Valid=36, Invalid=96, Unknown=0, NotChecked=0, Total=132 [2022-02-14 20:51:02,605 INFO L933 BasicCegarLoop]: 23 mSDtfsCounter, 29 mSDsluCounter, 22 mSDsCounter, 0 mSdLazyCounter, 130 mSolverCounterSat, 27 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.1s Time, 0 mProtectedPredicate, 0 mProtectedAction, 29 SdHoareTripleChecker+Valid, 45 SdHoareTripleChecker+Invalid, 157 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 27 IncrementalHoareTripleChecker+Valid, 130 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.1s IncrementalHoareTripleChecker+Time [2022-02-14 20:51:02,606 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [29 Valid, 45 Invalid, 157 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [27 Valid, 130 Invalid, 0 Unknown, 0 Unchecked, 0.1s Time] [2022-02-14 20:51:02,610 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 39 states. [2022-02-14 20:51:02,619 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 39 to 33. [2022-02-14 20:51:02,619 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 33 states, 23 states have (on average 1.173913043478261) internal successors, (27), 24 states have internal predecessors, (27), 5 states have call successors, (5), 5 states have call predecessors, (5), 4 states have return successors, (4), 4 states have call predecessors, (4), 4 states have call successors, (4) [2022-02-14 20:51:02,622 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 33 states to 33 states and 36 transitions. [2022-02-14 20:51:02,622 INFO L78 Accepts]: Start accepts. Automaton has 33 states and 36 transitions. Word has length 17 [2022-02-14 20:51:02,623 INFO L84 Accepts]: Finished accepts. word is rejected. [2022-02-14 20:51:02,623 INFO L470 AbstractCegarLoop]: Abstraction has 33 states and 36 transitions. [2022-02-14 20:51:02,624 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 7 states, 7 states have (on average 1.8571428571428572) internal successors, (13), 5 states have internal predecessors, (13), 2 states have call successors, (3), 3 states have call predecessors, (3), 1 states have return successors, (1), 1 states have call predecessors, (1), 1 states have call successors, (1) [2022-02-14 20:51:02,626 INFO L276 IsEmpty]: Start isEmpty. Operand 33 states and 36 transitions. [2022-02-14 20:51:02,626 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 22 [2022-02-14 20:51:02,627 INFO L506 BasicCegarLoop]: Found error trace [2022-02-14 20:51:02,627 INFO L514 BasicCegarLoop]: trace histogram [2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2022-02-14 20:51:02,627 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable1 [2022-02-14 20:51:02,627 INFO L402 AbstractCegarLoop]: === Iteration 3 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2022-02-14 20:51:02,628 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2022-02-14 20:51:02,628 INFO L85 PathProgramCache]: Analyzing trace with hash 1187235258, now seen corresponding path program 1 times [2022-02-14 20:51:02,628 INFO L126 FreeRefinementEngine]: Executing refinement strategy CAMEL [2022-02-14 20:51:02,628 INFO L338 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1120046188] [2022-02-14 20:51:02,628 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2022-02-14 20:51:02,629 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2022-02-14 20:51:02,654 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:02,721 INFO L376 atingTraceCheckCraig]: Compute interpolants for subsequence at non-pending call position 0 [2022-02-14 20:51:02,729 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:02,743 INFO L376 atingTraceCheckCraig]: Compute interpolants for subsequence at non-pending call position 12 [2022-02-14 20:51:02,748 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:02,760 INFO L134 CoverageAnalysis]: Checked inductivity of 2 backedges. 2 proven. 0 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2022-02-14 20:51:02,760 INFO L144 FreeRefinementEngine]: Strategy CAMEL found an infeasible trace [2022-02-14 20:51:02,760 INFO L338 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1120046188] [2022-02-14 20:51:02,760 INFO L165 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1120046188] provided 1 perfect and 0 imperfect interpolant sequences [2022-02-14 20:51:02,761 INFO L191 FreeRefinementEngine]: Found 1 perfect and 0 imperfect interpolant sequences. [2022-02-14 20:51:02,761 INFO L204 FreeRefinementEngine]: Number of different interpolants: perfect sequences [6] imperfect sequences [] total 6 [2022-02-14 20:51:02,761 INFO L118 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [783491199] [2022-02-14 20:51:02,761 INFO L85 oduleStraightlineAll]: Using 1 perfect interpolants to construct interpolant automaton [2022-02-14 20:51:02,761 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 6 states [2022-02-14 20:51:02,762 INFO L108 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy CAMEL [2022-02-14 20:51:02,762 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 6 interpolants. [2022-02-14 20:51:02,762 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=9, Invalid=21, Unknown=0, NotChecked=0, Total=30 [2022-02-14 20:51:02,762 INFO L87 Difference]: Start difference. First operand 33 states and 36 transitions. Second operand has 6 states, 6 states have (on average 2.5) internal successors, (15), 4 states have internal predecessors, (15), 2 states have call successors, (4), 3 states have call predecessors, (4), 1 states have return successors, (2), 2 states have call predecessors, (2), 2 states have call successors, (2) [2022-02-14 20:51:02,873 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2022-02-14 20:51:02,874 INFO L93 Difference]: Finished difference Result 44 states and 50 transitions. [2022-02-14 20:51:02,874 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 7 states. [2022-02-14 20:51:02,874 INFO L78 Accepts]: Start accepts. Automaton has has 6 states, 6 states have (on average 2.5) internal successors, (15), 4 states have internal predecessors, (15), 2 states have call successors, (4), 3 states have call predecessors, (4), 1 states have return successors, (2), 2 states have call predecessors, (2), 2 states have call successors, (2) Word has length 21 [2022-02-14 20:51:02,875 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2022-02-14 20:51:02,876 INFO L225 Difference]: With dead ends: 44 [2022-02-14 20:51:02,876 INFO L226 Difference]: Without dead ends: 44 [2022-02-14 20:51:02,879 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 14 GetRequests, 6 SyntacticMatches, 0 SemanticMatches, 8 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 4 ImplicationChecksByTransitivity, 0.0s TimeCoverageRelationStatistics Valid=28, Invalid=62, Unknown=0, NotChecked=0, Total=90 [2022-02-14 20:51:02,884 INFO L933 BasicCegarLoop]: 25 mSDtfsCounter, 31 mSDsluCounter, 17 mSDsCounter, 0 mSdLazyCounter, 90 mSolverCounterSat, 14 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.1s Time, 0 mProtectedPredicate, 0 mProtectedAction, 33 SdHoareTripleChecker+Valid, 42 SdHoareTripleChecker+Invalid, 104 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 14 IncrementalHoareTripleChecker+Valid, 90 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.1s IncrementalHoareTripleChecker+Time [2022-02-14 20:51:02,886 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [33 Valid, 42 Invalid, 104 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [14 Valid, 90 Invalid, 0 Unknown, 0 Unchecked, 0.1s Time] [2022-02-14 20:51:02,888 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 44 states. [2022-02-14 20:51:02,898 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 44 to 44. [2022-02-14 20:51:02,898 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 44 states, 31 states have (on average 1.1935483870967742) internal successors, (37), 32 states have internal predecessors, (37), 7 states have call successors, (7), 6 states have call predecessors, (7), 5 states have return successors, (6), 6 states have call predecessors, (6), 6 states have call successors, (6) [2022-02-14 20:51:02,900 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 44 states to 44 states and 50 transitions. [2022-02-14 20:51:02,900 INFO L78 Accepts]: Start accepts. Automaton has 44 states and 50 transitions. Word has length 21 [2022-02-14 20:51:02,900 INFO L84 Accepts]: Finished accepts. word is rejected. [2022-02-14 20:51:02,900 INFO L470 AbstractCegarLoop]: Abstraction has 44 states and 50 transitions. [2022-02-14 20:51:02,900 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 6 states, 6 states have (on average 2.5) internal successors, (15), 4 states have internal predecessors, (15), 2 states have call successors, (4), 3 states have call predecessors, (4), 1 states have return successors, (2), 2 states have call predecessors, (2), 2 states have call successors, (2) [2022-02-14 20:51:02,901 INFO L276 IsEmpty]: Start isEmpty. Operand 44 states and 50 transitions. [2022-02-14 20:51:02,902 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 26 [2022-02-14 20:51:02,902 INFO L506 BasicCegarLoop]: Found error trace [2022-02-14 20:51:02,902 INFO L514 BasicCegarLoop]: trace histogram [2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2022-02-14 20:51:02,903 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable2 [2022-02-14 20:51:02,903 INFO L402 AbstractCegarLoop]: === Iteration 4 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2022-02-14 20:51:02,904 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2022-02-14 20:51:02,904 INFO L85 PathProgramCache]: Analyzing trace with hash -1420692427, now seen corresponding path program 1 times [2022-02-14 20:51:02,904 INFO L126 FreeRefinementEngine]: Executing refinement strategy CAMEL [2022-02-14 20:51:02,904 INFO L338 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [219581640] [2022-02-14 20:51:02,905 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2022-02-14 20:51:02,905 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2022-02-14 20:51:02,927 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:03,011 INFO L376 atingTraceCheckCraig]: Compute interpolants for subsequence at non-pending call position 0 [2022-02-14 20:51:03,015 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:03,024 INFO L376 atingTraceCheckCraig]: Compute interpolants for subsequence at non-pending call position 16 [2022-02-14 20:51:03,026 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:03,032 INFO L134 CoverageAnalysis]: Checked inductivity of 4 backedges. 2 proven. 2 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2022-02-14 20:51:03,032 INFO L144 FreeRefinementEngine]: Strategy CAMEL found an infeasible trace [2022-02-14 20:51:03,033 INFO L338 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [219581640] [2022-02-14 20:51:03,033 INFO L165 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [219581640] provided 0 perfect and 1 imperfect interpolant sequences [2022-02-14 20:51:03,033 INFO L338 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1418334677] [2022-02-14 20:51:03,033 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2022-02-14 20:51:03,033 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2022-02-14 20:51:03,034 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2022-02-14 20:51:03,035 INFO L229 MonitoredProcess]: Starting monitored process 2 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2022-02-14 20:51:03,044 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (2)] Waiting until timeout for monitored process [2022-02-14 20:51:03,088 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:03,090 INFO L263 TraceCheckSpWp]: Trace formula consists of 83 conjuncts, 5 conjunts are in the unsatisfiable core [2022-02-14 20:51:03,101 INFO L286 TraceCheckSpWp]: Computing forward predicates... [2022-02-14 20:51:03,409 INFO L134 CoverageAnalysis]: Checked inductivity of 4 backedges. 2 proven. 0 refuted. 0 times theorem prover too weak. 2 trivial. 0 not checked. [2022-02-14 20:51:03,409 INFO L324 TraceCheckSpWp]: Omiting computation of backward sequence because forward sequence was already perfect [2022-02-14 20:51:03,409 INFO L165 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1418334677] provided 1 perfect and 0 imperfect interpolant sequences [2022-02-14 20:51:03,409 INFO L191 FreeRefinementEngine]: Found 1 perfect and 1 imperfect interpolant sequences. [2022-02-14 20:51:03,409 INFO L204 FreeRefinementEngine]: Number of different interpolants: perfect sequences [5] imperfect sequences [8] total 11 [2022-02-14 20:51:03,410 INFO L118 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [243931416] [2022-02-14 20:51:03,410 INFO L85 oduleStraightlineAll]: Using 1 perfect interpolants to construct interpolant automaton [2022-02-14 20:51:03,410 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 5 states [2022-02-14 20:51:03,410 INFO L108 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy CAMEL [2022-02-14 20:51:03,411 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 5 interpolants. [2022-02-14 20:51:03,411 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=22, Invalid=88, Unknown=0, NotChecked=0, Total=110 [2022-02-14 20:51:03,411 INFO L87 Difference]: Start difference. First operand 44 states and 50 transitions. Second operand has 5 states, 5 states have (on average 3.6) internal successors, (18), 5 states have internal predecessors, (18), 2 states have call successors, (4), 2 states have call predecessors, (4), 2 states have return successors, (2), 2 states have call predecessors, (2), 2 states have call successors, (2) [2022-02-14 20:51:03,484 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2022-02-14 20:51:03,484 INFO L93 Difference]: Finished difference Result 72 states and 94 transitions. [2022-02-14 20:51:03,484 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 5 states. [2022-02-14 20:51:03,484 INFO L78 Accepts]: Start accepts. Automaton has has 5 states, 5 states have (on average 3.6) internal successors, (18), 5 states have internal predecessors, (18), 2 states have call successors, (4), 2 states have call predecessors, (4), 2 states have return successors, (2), 2 states have call predecessors, (2), 2 states have call successors, (2) Word has length 25 [2022-02-14 20:51:03,485 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2022-02-14 20:51:03,487 INFO L225 Difference]: With dead ends: 72 [2022-02-14 20:51:03,487 INFO L226 Difference]: Without dead ends: 72 [2022-02-14 20:51:03,488 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 37 GetRequests, 26 SyntacticMatches, 0 SemanticMatches, 11 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 4 ImplicationChecksByTransitivity, 0.1s TimeCoverageRelationStatistics Valid=35, Invalid=121, Unknown=0, NotChecked=0, Total=156 [2022-02-14 20:51:03,494 INFO L933 BasicCegarLoop]: 29 mSDtfsCounter, 22 mSDsluCounter, 70 mSDsCounter, 0 mSdLazyCounter, 37 mSolverCounterSat, 13 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.0s Time, 0 mProtectedPredicate, 0 mProtectedAction, 25 SdHoareTripleChecker+Valid, 99 SdHoareTripleChecker+Invalid, 50 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 13 IncrementalHoareTripleChecker+Valid, 37 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.0s IncrementalHoareTripleChecker+Time [2022-02-14 20:51:03,495 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [25 Valid, 99 Invalid, 50 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [13 Valid, 37 Invalid, 0 Unknown, 0 Unchecked, 0.0s Time] [2022-02-14 20:51:03,496 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 72 states. [2022-02-14 20:51:03,503 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 72 to 48. [2022-02-14 20:51:03,503 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 48 states, 35 states have (on average 1.2) internal successors, (42), 36 states have internal predecessors, (42), 7 states have call successors, (7), 6 states have call predecessors, (7), 5 states have return successors, (6), 6 states have call predecessors, (6), 6 states have call successors, (6) [2022-02-14 20:51:03,504 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 48 states to 48 states and 55 transitions. [2022-02-14 20:51:03,504 INFO L78 Accepts]: Start accepts. Automaton has 48 states and 55 transitions. Word has length 25 [2022-02-14 20:51:03,504 INFO L84 Accepts]: Finished accepts. word is rejected. [2022-02-14 20:51:03,504 INFO L470 AbstractCegarLoop]: Abstraction has 48 states and 55 transitions. [2022-02-14 20:51:03,505 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 5 states, 5 states have (on average 3.6) internal successors, (18), 5 states have internal predecessors, (18), 2 states have call successors, (4), 2 states have call predecessors, (4), 2 states have return successors, (2), 2 states have call predecessors, (2), 2 states have call successors, (2) [2022-02-14 20:51:03,505 INFO L276 IsEmpty]: Start isEmpty. Operand 48 states and 55 transitions. [2022-02-14 20:51:03,505 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 33 [2022-02-14 20:51:03,506 INFO L506 BasicCegarLoop]: Found error trace [2022-02-14 20:51:03,506 INFO L514 BasicCegarLoop]: trace histogram [3, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2022-02-14 20:51:03,527 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (2)] Forceful destruction successful, exit code 0 [2022-02-14 20:51:03,706 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable3,2 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2022-02-14 20:51:03,707 INFO L402 AbstractCegarLoop]: === Iteration 5 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2022-02-14 20:51:03,707 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2022-02-14 20:51:03,707 INFO L85 PathProgramCache]: Analyzing trace with hash 1754984885, now seen corresponding path program 1 times [2022-02-14 20:51:03,707 INFO L126 FreeRefinementEngine]: Executing refinement strategy CAMEL [2022-02-14 20:51:03,708 INFO L338 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1780793603] [2022-02-14 20:51:03,708 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2022-02-14 20:51:03,708 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2022-02-14 20:51:03,725 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:03,815 INFO L376 atingTraceCheckCraig]: Compute interpolants for subsequence at non-pending call position 0 [2022-02-14 20:51:03,817 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:03,822 INFO L376 atingTraceCheckCraig]: Compute interpolants for subsequence at non-pending call position 13 [2022-02-14 20:51:03,839 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:03,855 INFO L376 atingTraceCheckCraig]: Compute interpolants for subsequence at non-pending call position 23 [2022-02-14 20:51:03,857 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:03,860 INFO L134 CoverageAnalysis]: Checked inductivity of 11 backedges. 4 proven. 3 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2022-02-14 20:51:03,860 INFO L144 FreeRefinementEngine]: Strategy CAMEL found an infeasible trace [2022-02-14 20:51:03,860 INFO L338 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1780793603] [2022-02-14 20:51:03,861 INFO L165 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1780793603] provided 0 perfect and 1 imperfect interpolant sequences [2022-02-14 20:51:03,861 INFO L338 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [389797375] [2022-02-14 20:51:03,861 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2022-02-14 20:51:03,861 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2022-02-14 20:51:03,861 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2022-02-14 20:51:03,872 INFO L229 MonitoredProcess]: Starting monitored process 3 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2022-02-14 20:51:03,900 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (3)] Waiting until timeout for monitored process [2022-02-14 20:51:03,928 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:03,929 INFO L263 TraceCheckSpWp]: Trace formula consists of 95 conjuncts, 5 conjunts are in the unsatisfiable core [2022-02-14 20:51:03,931 INFO L286 TraceCheckSpWp]: Computing forward predicates... [2022-02-14 20:51:04,052 INFO L134 CoverageAnalysis]: Checked inductivity of 11 backedges. 8 proven. 1 refuted. 0 times theorem prover too weak. 2 trivial. 0 not checked. [2022-02-14 20:51:04,052 INFO L328 TraceCheckSpWp]: Computing backward predicates... [2022-02-14 20:51:04,130 INFO L134 CoverageAnalysis]: Checked inductivity of 11 backedges. 6 proven. 1 refuted. 0 times theorem prover too weak. 4 trivial. 0 not checked. [2022-02-14 20:51:04,130 INFO L165 FreeRefinementEngine]: IpTcStrategyModuleZ3 [389797375] provided 0 perfect and 2 imperfect interpolant sequences [2022-02-14 20:51:04,130 INFO L191 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2022-02-14 20:51:04,130 INFO L204 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [10, 6, 6] total 14 [2022-02-14 20:51:04,131 INFO L118 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [294917279] [2022-02-14 20:51:04,131 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2022-02-14 20:51:04,131 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 14 states [2022-02-14 20:51:04,131 INFO L108 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy CAMEL [2022-02-14 20:51:04,132 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 14 interpolants. [2022-02-14 20:51:04,132 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=32, Invalid=150, Unknown=0, NotChecked=0, Total=182 [2022-02-14 20:51:04,132 INFO L87 Difference]: Start difference. First operand 48 states and 55 transitions. Second operand has 14 states, 14 states have (on average 2.5714285714285716) internal successors, (36), 11 states have internal predecessors, (36), 5 states have call successors, (10), 4 states have call predecessors, (10), 2 states have return successors, (6), 5 states have call predecessors, (6), 5 states have call successors, (6) [2022-02-14 20:51:04,646 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2022-02-14 20:51:04,646 INFO L93 Difference]: Finished difference Result 94 states and 121 transitions. [2022-02-14 20:51:04,646 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 24 states. [2022-02-14 20:51:04,646 INFO L78 Accepts]: Start accepts. Automaton has has 14 states, 14 states have (on average 2.5714285714285716) internal successors, (36), 11 states have internal predecessors, (36), 5 states have call successors, (10), 4 states have call predecessors, (10), 2 states have return successors, (6), 5 states have call predecessors, (6), 5 states have call successors, (6) Word has length 32 [2022-02-14 20:51:04,647 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2022-02-14 20:51:04,648 INFO L225 Difference]: With dead ends: 94 [2022-02-14 20:51:04,648 INFO L226 Difference]: Without dead ends: 94 [2022-02-14 20:51:04,648 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 102 GetRequests, 68 SyntacticMatches, 1 SemanticMatches, 33 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 258 ImplicationChecksByTransitivity, 0.3s TimeCoverageRelationStatistics Valid=231, Invalid=959, Unknown=0, NotChecked=0, Total=1190 [2022-02-14 20:51:04,649 INFO L933 BasicCegarLoop]: 19 mSDtfsCounter, 89 mSDsluCounter, 42 mSDsCounter, 0 mSdLazyCounter, 299 mSolverCounterSat, 105 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.2s Time, 0 mProtectedPredicate, 0 mProtectedAction, 91 SdHoareTripleChecker+Valid, 61 SdHoareTripleChecker+Invalid, 404 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 105 IncrementalHoareTripleChecker+Valid, 299 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.2s IncrementalHoareTripleChecker+Time [2022-02-14 20:51:04,649 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [91 Valid, 61 Invalid, 404 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [105 Valid, 299 Invalid, 0 Unknown, 0 Unchecked, 0.2s Time] [2022-02-14 20:51:04,650 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 94 states. [2022-02-14 20:51:04,655 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 94 to 66. [2022-02-14 20:51:04,655 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 66 states, 48 states have (on average 1.25) internal successors, (60), 50 states have internal predecessors, (60), 12 states have call successors, (12), 6 states have call predecessors, (12), 5 states have return successors, (11), 11 states have call predecessors, (11), 11 states have call successors, (11) [2022-02-14 20:51:04,656 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 66 states to 66 states and 83 transitions. [2022-02-14 20:51:04,656 INFO L78 Accepts]: Start accepts. Automaton has 66 states and 83 transitions. Word has length 32 [2022-02-14 20:51:04,656 INFO L84 Accepts]: Finished accepts. word is rejected. [2022-02-14 20:51:04,656 INFO L470 AbstractCegarLoop]: Abstraction has 66 states and 83 transitions. [2022-02-14 20:51:04,657 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 14 states, 14 states have (on average 2.5714285714285716) internal successors, (36), 11 states have internal predecessors, (36), 5 states have call successors, (10), 4 states have call predecessors, (10), 2 states have return successors, (6), 5 states have call predecessors, (6), 5 states have call successors, (6) [2022-02-14 20:51:04,657 INFO L276 IsEmpty]: Start isEmpty. Operand 66 states and 83 transitions. [2022-02-14 20:51:04,658 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 43 [2022-02-14 20:51:04,658 INFO L506 BasicCegarLoop]: Found error trace [2022-02-14 20:51:04,658 INFO L514 BasicCegarLoop]: trace histogram [3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2022-02-14 20:51:04,683 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (3)] Forceful destruction successful, exit code 0 [2022-02-14 20:51:04,872 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable4,3 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2022-02-14 20:51:04,873 INFO L402 AbstractCegarLoop]: === Iteration 6 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2022-02-14 20:51:04,874 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2022-02-14 20:51:04,874 INFO L85 PathProgramCache]: Analyzing trace with hash -1763990758, now seen corresponding path program 1 times [2022-02-14 20:51:04,874 INFO L126 FreeRefinementEngine]: Executing refinement strategy CAMEL [2022-02-14 20:51:04,874 INFO L338 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [551982529] [2022-02-14 20:51:04,874 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2022-02-14 20:51:04,874 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2022-02-14 20:51:04,890 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:04,961 INFO L376 atingTraceCheckCraig]: Compute interpolants for subsequence at non-pending call position 0 [2022-02-14 20:51:04,963 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:04,977 INFO L376 atingTraceCheckCraig]: Compute interpolants for subsequence at non-pending call position 13 [2022-02-14 20:51:04,979 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:04,986 INFO L376 atingTraceCheckCraig]: Compute interpolants for subsequence at non-pending call position 33 [2022-02-14 20:51:04,987 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:04,992 INFO L134 CoverageAnalysis]: Checked inductivity of 29 backedges. 18 proven. 3 refuted. 0 times theorem prover too weak. 8 trivial. 0 not checked. [2022-02-14 20:51:04,992 INFO L144 FreeRefinementEngine]: Strategy CAMEL found an infeasible trace [2022-02-14 20:51:04,992 INFO L338 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [551982529] [2022-02-14 20:51:04,992 INFO L165 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [551982529] provided 0 perfect and 1 imperfect interpolant sequences [2022-02-14 20:51:04,992 INFO L338 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [882769140] [2022-02-14 20:51:04,992 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2022-02-14 20:51:04,993 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2022-02-14 20:51:04,993 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2022-02-14 20:51:04,996 INFO L229 MonitoredProcess]: Starting monitored process 4 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2022-02-14 20:51:05,006 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (4)] Waiting until timeout for monitored process [2022-02-14 20:51:05,042 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:05,043 INFO L263 TraceCheckSpWp]: Trace formula consists of 116 conjuncts, 7 conjunts are in the unsatisfiable core [2022-02-14 20:51:05,045 INFO L286 TraceCheckSpWp]: Computing forward predicates... [2022-02-14 20:51:05,219 INFO L134 CoverageAnalysis]: Checked inductivity of 29 backedges. 20 proven. 3 refuted. 0 times theorem prover too weak. 6 trivial. 0 not checked. [2022-02-14 20:51:05,219 INFO L328 TraceCheckSpWp]: Computing backward predicates... [2022-02-14 20:51:05,321 INFO L134 CoverageAnalysis]: Checked inductivity of 29 backedges. 18 proven. 3 refuted. 0 times theorem prover too weak. 8 trivial. 0 not checked. [2022-02-14 20:51:05,321 INFO L165 FreeRefinementEngine]: IpTcStrategyModuleZ3 [882769140] provided 0 perfect and 2 imperfect interpolant sequences [2022-02-14 20:51:05,322 INFO L191 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2022-02-14 20:51:05,322 INFO L204 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [9, 8, 8] total 19 [2022-02-14 20:51:05,322 INFO L118 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [2028059514] [2022-02-14 20:51:05,322 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2022-02-14 20:51:05,323 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 19 states [2022-02-14 20:51:05,323 INFO L108 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy CAMEL [2022-02-14 20:51:05,324 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 19 interpolants. [2022-02-14 20:51:05,324 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=69, Invalid=273, Unknown=0, NotChecked=0, Total=342 [2022-02-14 20:51:05,324 INFO L87 Difference]: Start difference. First operand 66 states and 83 transitions. Second operand has 19 states, 19 states have (on average 2.789473684210526) internal successors, (53), 18 states have internal predecessors, (53), 5 states have call successors, (9), 3 states have call predecessors, (9), 2 states have return successors, (6), 5 states have call predecessors, (6), 5 states have call successors, (6) [2022-02-14 20:51:05,595 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2022-02-14 20:51:05,595 INFO L93 Difference]: Finished difference Result 86 states and 110 transitions. [2022-02-14 20:51:05,595 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 10 states. [2022-02-14 20:51:05,596 INFO L78 Accepts]: Start accepts. Automaton has has 19 states, 19 states have (on average 2.789473684210526) internal successors, (53), 18 states have internal predecessors, (53), 5 states have call successors, (9), 3 states have call predecessors, (9), 2 states have return successors, (6), 5 states have call predecessors, (6), 5 states have call successors, (6) Word has length 42 [2022-02-14 20:51:05,596 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2022-02-14 20:51:05,597 INFO L225 Difference]: With dead ends: 86 [2022-02-14 20:51:05,597 INFO L226 Difference]: Without dead ends: 82 [2022-02-14 20:51:05,597 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 104 GetRequests, 79 SyntacticMatches, 1 SemanticMatches, 24 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 160 ImplicationChecksByTransitivity, 0.2s TimeCoverageRelationStatistics Valid=151, Invalid=499, Unknown=0, NotChecked=0, Total=650 [2022-02-14 20:51:05,598 INFO L933 BasicCegarLoop]: 18 mSDtfsCounter, 62 mSDsluCounter, 42 mSDsCounter, 0 mSdLazyCounter, 297 mSolverCounterSat, 49 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.1s Time, 0 mProtectedPredicate, 0 mProtectedAction, 65 SdHoareTripleChecker+Valid, 60 SdHoareTripleChecker+Invalid, 346 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 49 IncrementalHoareTripleChecker+Valid, 297 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.2s IncrementalHoareTripleChecker+Time [2022-02-14 20:51:05,598 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [65 Valid, 60 Invalid, 346 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [49 Valid, 297 Invalid, 0 Unknown, 0 Unchecked, 0.2s Time] [2022-02-14 20:51:05,598 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 82 states. [2022-02-14 20:51:05,603 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 82 to 71. [2022-02-14 20:51:05,603 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 71 states, 52 states have (on average 1.25) internal successors, (65), 54 states have internal predecessors, (65), 13 states have call successors, (13), 6 states have call predecessors, (13), 5 states have return successors, (12), 12 states have call predecessors, (12), 12 states have call successors, (12) [2022-02-14 20:51:05,604 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 71 states to 71 states and 90 transitions. [2022-02-14 20:51:05,604 INFO L78 Accepts]: Start accepts. Automaton has 71 states and 90 transitions. Word has length 42 [2022-02-14 20:51:05,604 INFO L84 Accepts]: Finished accepts. word is rejected. [2022-02-14 20:51:05,604 INFO L470 AbstractCegarLoop]: Abstraction has 71 states and 90 transitions. [2022-02-14 20:51:05,604 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 19 states, 19 states have (on average 2.789473684210526) internal successors, (53), 18 states have internal predecessors, (53), 5 states have call successors, (9), 3 states have call predecessors, (9), 2 states have return successors, (6), 5 states have call predecessors, (6), 5 states have call successors, (6) [2022-02-14 20:51:05,605 INFO L276 IsEmpty]: Start isEmpty. Operand 71 states and 90 transitions. [2022-02-14 20:51:05,606 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 45 [2022-02-14 20:51:05,606 INFO L506 BasicCegarLoop]: Found error trace [2022-02-14 20:51:05,606 INFO L514 BasicCegarLoop]: trace histogram [4, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2022-02-14 20:51:05,631 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (4)] Forceful destruction successful, exit code 0 [2022-02-14 20:51:05,831 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable5,4 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2022-02-14 20:51:05,832 INFO L402 AbstractCegarLoop]: === Iteration 7 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2022-02-14 20:51:05,832 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2022-02-14 20:51:05,832 INFO L85 PathProgramCache]: Analyzing trace with hash 1192666941, now seen corresponding path program 1 times [2022-02-14 20:51:05,832 INFO L126 FreeRefinementEngine]: Executing refinement strategy CAMEL [2022-02-14 20:51:05,832 INFO L338 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [793725819] [2022-02-14 20:51:05,833 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2022-02-14 20:51:05,833 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2022-02-14 20:51:05,843 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:05,898 INFO L376 atingTraceCheckCraig]: Compute interpolants for subsequence at non-pending call position 0 [2022-02-14 20:51:05,899 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:05,903 INFO L376 atingTraceCheckCraig]: Compute interpolants for subsequence at non-pending call position 12 [2022-02-14 20:51:05,905 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:05,908 INFO L376 atingTraceCheckCraig]: Compute interpolants for subsequence at non-pending call position 17 [2022-02-14 20:51:05,910 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:05,915 INFO L376 atingTraceCheckCraig]: Compute interpolants for subsequence at non-pending call position 35 [2022-02-14 20:51:05,916 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:05,923 INFO L134 CoverageAnalysis]: Checked inductivity of 38 backedges. 20 proven. 2 refuted. 0 times theorem prover too weak. 16 trivial. 0 not checked. [2022-02-14 20:51:05,923 INFO L144 FreeRefinementEngine]: Strategy CAMEL found an infeasible trace [2022-02-14 20:51:05,923 INFO L338 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [793725819] [2022-02-14 20:51:05,923 INFO L165 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [793725819] provided 0 perfect and 1 imperfect interpolant sequences [2022-02-14 20:51:05,923 INFO L338 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [2042084754] [2022-02-14 20:51:05,923 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2022-02-14 20:51:05,924 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2022-02-14 20:51:05,924 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2022-02-14 20:51:05,925 INFO L229 MonitoredProcess]: Starting monitored process 5 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2022-02-14 20:51:05,928 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (5)] Waiting until timeout for monitored process [2022-02-14 20:51:05,970 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:05,971 INFO L263 TraceCheckSpWp]: Trace formula consists of 120 conjuncts, 6 conjunts are in the unsatisfiable core [2022-02-14 20:51:05,973 INFO L286 TraceCheckSpWp]: Computing forward predicates... [2022-02-14 20:51:06,122 INFO L134 CoverageAnalysis]: Checked inductivity of 38 backedges. 26 proven. 2 refuted. 0 times theorem prover too weak. 10 trivial. 0 not checked. [2022-02-14 20:51:06,122 INFO L328 TraceCheckSpWp]: Computing backward predicates... [2022-02-14 20:51:06,218 INFO L134 CoverageAnalysis]: Checked inductivity of 38 backedges. 20 proven. 2 refuted. 0 times theorem prover too weak. 16 trivial. 0 not checked. [2022-02-14 20:51:06,219 INFO L165 FreeRefinementEngine]: IpTcStrategyModuleZ3 [2042084754] provided 0 perfect and 2 imperfect interpolant sequences [2022-02-14 20:51:06,219 INFO L191 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2022-02-14 20:51:06,219 INFO L204 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [8, 7, 7] total 16 [2022-02-14 20:51:06,219 INFO L118 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [399686752] [2022-02-14 20:51:06,219 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2022-02-14 20:51:06,220 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 16 states [2022-02-14 20:51:06,220 INFO L108 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy CAMEL [2022-02-14 20:51:06,221 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 16 interpolants. [2022-02-14 20:51:06,221 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=57, Invalid=183, Unknown=0, NotChecked=0, Total=240 [2022-02-14 20:51:06,221 INFO L87 Difference]: Start difference. First operand 71 states and 90 transitions. Second operand has 16 states, 16 states have (on average 2.75) internal successors, (44), 15 states have internal predecessors, (44), 5 states have call successors, (12), 3 states have call predecessors, (12), 2 states have return successors, (9), 5 states have call predecessors, (9), 5 states have call successors, (9) [2022-02-14 20:51:06,453 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2022-02-14 20:51:06,453 INFO L93 Difference]: Finished difference Result 95 states and 125 transitions. [2022-02-14 20:51:06,453 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 8 states. [2022-02-14 20:51:06,453 INFO L78 Accepts]: Start accepts. Automaton has has 16 states, 16 states have (on average 2.75) internal successors, (44), 15 states have internal predecessors, (44), 5 states have call successors, (12), 3 states have call predecessors, (12), 2 states have return successors, (9), 5 states have call predecessors, (9), 5 states have call successors, (9) Word has length 44 [2022-02-14 20:51:06,454 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2022-02-14 20:51:06,454 INFO L225 Difference]: With dead ends: 95 [2022-02-14 20:51:06,454 INFO L226 Difference]: Without dead ends: 93 [2022-02-14 20:51:06,455 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 107 GetRequests, 87 SyntacticMatches, 1 SemanticMatches, 19 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 101 ImplicationChecksByTransitivity, 0.1s TimeCoverageRelationStatistics Valid=105, Invalid=315, Unknown=0, NotChecked=0, Total=420 [2022-02-14 20:51:06,455 INFO L933 BasicCegarLoop]: 21 mSDtfsCounter, 94 mSDsluCounter, 47 mSDsCounter, 0 mSdLazyCounter, 303 mSolverCounterSat, 53 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.1s Time, 0 mProtectedPredicate, 0 mProtectedAction, 97 SdHoareTripleChecker+Valid, 68 SdHoareTripleChecker+Invalid, 356 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 53 IncrementalHoareTripleChecker+Valid, 303 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.2s IncrementalHoareTripleChecker+Time [2022-02-14 20:51:06,456 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [97 Valid, 68 Invalid, 356 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [53 Valid, 303 Invalid, 0 Unknown, 0 Unchecked, 0.2s Time] [2022-02-14 20:51:06,456 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 93 states. [2022-02-14 20:51:06,460 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 93 to 78. [2022-02-14 20:51:06,461 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 78 states, 56 states have (on average 1.25) internal successors, (70), 59 states have internal predecessors, (70), 16 states have call successors, (16), 6 states have call predecessors, (16), 5 states have return successors, (15), 15 states have call predecessors, (15), 15 states have call successors, (15) [2022-02-14 20:51:06,462 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 78 states to 78 states and 101 transitions. [2022-02-14 20:51:06,462 INFO L78 Accepts]: Start accepts. Automaton has 78 states and 101 transitions. Word has length 44 [2022-02-14 20:51:06,462 INFO L84 Accepts]: Finished accepts. word is rejected. [2022-02-14 20:51:06,462 INFO L470 AbstractCegarLoop]: Abstraction has 78 states and 101 transitions. [2022-02-14 20:51:06,462 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 16 states, 16 states have (on average 2.75) internal successors, (44), 15 states have internal predecessors, (44), 5 states have call successors, (12), 3 states have call predecessors, (12), 2 states have return successors, (9), 5 states have call predecessors, (9), 5 states have call successors, (9) [2022-02-14 20:51:06,462 INFO L276 IsEmpty]: Start isEmpty. Operand 78 states and 101 transitions. [2022-02-14 20:51:06,464 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 56 [2022-02-14 20:51:06,464 INFO L506 BasicCegarLoop]: Found error trace [2022-02-14 20:51:06,464 INFO L514 BasicCegarLoop]: trace histogram [5, 4, 4, 4, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2022-02-14 20:51:06,489 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (5)] Forceful destruction successful, exit code 0 [2022-02-14 20:51:06,687 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable6,5 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2022-02-14 20:51:06,687 INFO L402 AbstractCegarLoop]: === Iteration 8 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2022-02-14 20:51:06,687 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2022-02-14 20:51:06,687 INFO L85 PathProgramCache]: Analyzing trace with hash 1839163900, now seen corresponding path program 1 times [2022-02-14 20:51:06,688 INFO L126 FreeRefinementEngine]: Executing refinement strategy CAMEL [2022-02-14 20:51:06,688 INFO L338 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [250119795] [2022-02-14 20:51:06,688 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2022-02-14 20:51:06,688 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2022-02-14 20:51:06,699 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:06,734 INFO L376 atingTraceCheckCraig]: Compute interpolants for subsequence at non-pending call position 0 [2022-02-14 20:51:06,735 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:06,738 INFO L376 atingTraceCheckCraig]: Compute interpolants for subsequence at non-pending call position 12 [2022-02-14 20:51:06,739 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:06,741 INFO L376 atingTraceCheckCraig]: Compute interpolants for subsequence at non-pending call position 17 [2022-02-14 20:51:06,741 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:06,743 INFO L376 atingTraceCheckCraig]: Compute interpolants for subsequence at non-pending call position 26 [2022-02-14 20:51:06,744 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:06,745 INFO L376 atingTraceCheckCraig]: Compute interpolants for subsequence at non-pending call position 46 [2022-02-14 20:51:06,746 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:06,750 INFO L134 CoverageAnalysis]: Checked inductivity of 65 backedges. 29 proven. 1 refuted. 0 times theorem prover too weak. 35 trivial. 0 not checked. [2022-02-14 20:51:06,750 INFO L144 FreeRefinementEngine]: Strategy CAMEL found an infeasible trace [2022-02-14 20:51:06,750 INFO L338 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [250119795] [2022-02-14 20:51:06,750 INFO L165 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [250119795] provided 0 perfect and 1 imperfect interpolant sequences [2022-02-14 20:51:06,750 INFO L338 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [831424671] [2022-02-14 20:51:06,751 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2022-02-14 20:51:06,751 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2022-02-14 20:51:06,751 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2022-02-14 20:51:06,752 INFO L229 MonitoredProcess]: Starting monitored process 6 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2022-02-14 20:51:06,783 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (6)] Waiting until timeout for monitored process [2022-02-14 20:51:06,798 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2022-02-14 20:51:06,799 INFO L263 TraceCheckSpWp]: Trace formula consists of 141 conjuncts, 8 conjunts are in the unsatisfiable core [2022-02-14 20:51:06,801 INFO L286 TraceCheckSpWp]: Computing forward predicates... [2022-02-14 20:51:06,956 INFO L134 CoverageAnalysis]: Checked inductivity of 65 backedges. 40 proven. 9 refuted. 0 times theorem prover too weak. 16 trivial. 0 not checked. [2022-02-14 20:51:06,956 INFO L328 TraceCheckSpWp]: Computing backward predicates... [2022-02-14 20:51:07,082 INFO L134 CoverageAnalysis]: Checked inductivity of 65 backedges. 30 proven. 9 refuted. 0 times theorem prover too weak. 26 trivial. 0 not checked. [2022-02-14 20:51:07,083 INFO L165 FreeRefinementEngine]: IpTcStrategyModuleZ3 [831424671] provided 0 perfect and 2 imperfect interpolant sequences [2022-02-14 20:51:07,083 INFO L191 FreeRefinementEngine]: Found 0 perfect and 3 imperfect interpolant sequences. [2022-02-14 20:51:07,083 INFO L204 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [7, 9, 9] total 15 [2022-02-14 20:51:07,083 INFO L118 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [2118932388] [2022-02-14 20:51:07,083 INFO L85 oduleStraightlineAll]: Using 3 imperfect interpolants to construct interpolant automaton [2022-02-14 20:51:07,084 INFO L546 AbstractCegarLoop]: INTERPOLANT automaton has 15 states [2022-02-14 20:51:07,084 INFO L108 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy CAMEL [2022-02-14 20:51:07,084 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 15 interpolants. [2022-02-14 20:51:07,085 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=31, Invalid=179, Unknown=0, NotChecked=0, Total=210 [2022-02-14 20:51:07,085 INFO L87 Difference]: Start difference. First operand 78 states and 101 transitions. Second operand has 15 states, 15 states have (on average 4.0) internal successors, (60), 13 states have internal predecessors, (60), 5 states have call successors, (14), 4 states have call predecessors, (14), 2 states have return successors, (10), 5 states have call predecessors, (10), 5 states have call successors, (10) [2022-02-14 20:51:07,782 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2022-02-14 20:51:07,782 INFO L93 Difference]: Finished difference Result 123 states and 169 transitions. [2022-02-14 20:51:07,783 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 31 states. [2022-02-14 20:51:07,783 INFO L78 Accepts]: Start accepts. Automaton has has 15 states, 15 states have (on average 4.0) internal successors, (60), 13 states have internal predecessors, (60), 5 states have call successors, (14), 4 states have call predecessors, (14), 2 states have return successors, (10), 5 states have call predecessors, (10), 5 states have call successors, (10) Word has length 55 [2022-02-14 20:51:07,783 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2022-02-14 20:51:07,783 INFO L225 Difference]: With dead ends: 123 [2022-02-14 20:51:07,783 INFO L226 Difference]: Without dead ends: 0 [2022-02-14 20:51:07,784 INFO L932 BasicCegarLoop]: 0 DeclaredPredicates, 153 GetRequests, 110 SyntacticMatches, 2 SemanticMatches, 41 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 378 ImplicationChecksByTransitivity, 0.5s TimeCoverageRelationStatistics Valid=344, Invalid=1462, Unknown=0, NotChecked=0, Total=1806 [2022-02-14 20:51:07,785 INFO L933 BasicCegarLoop]: 17 mSDtfsCounter, 82 mSDsluCounter, 62 mSDsCounter, 0 mSdLazyCounter, 446 mSolverCounterSat, 115 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.2s Time, 0 mProtectedPredicate, 0 mProtectedAction, 82 SdHoareTripleChecker+Valid, 79 SdHoareTripleChecker+Invalid, 561 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 115 IncrementalHoareTripleChecker+Valid, 446 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.3s IncrementalHoareTripleChecker+Time [2022-02-14 20:51:07,785 INFO L934 BasicCegarLoop]: SdHoareTripleChecker [82 Valid, 79 Invalid, 561 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [115 Valid, 446 Invalid, 0 Unknown, 0 Unchecked, 0.3s Time] [2022-02-14 20:51:07,785 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 0 states. [2022-02-14 20:51:07,785 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 0 to 0. [2022-02-14 20:51:07,786 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 0 states, 0 states have (on average 0.0) internal successors, (0), 0 states have internal predecessors, (0), 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) [2022-02-14 20:51:07,786 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 0 states to 0 states and 0 transitions. [2022-02-14 20:51:07,786 INFO L78 Accepts]: Start accepts. Automaton has 0 states and 0 transitions. Word has length 55 [2022-02-14 20:51:07,786 INFO L84 Accepts]: Finished accepts. word is rejected. [2022-02-14 20:51:07,786 INFO L470 AbstractCegarLoop]: Abstraction has 0 states and 0 transitions. [2022-02-14 20:51:07,786 INFO L471 AbstractCegarLoop]: INTERPOLANT automaton has has 15 states, 15 states have (on average 4.0) internal successors, (60), 13 states have internal predecessors, (60), 5 states have call successors, (14), 4 states have call predecessors, (14), 2 states have return successors, (10), 5 states have call predecessors, (10), 5 states have call successors, (10) [2022-02-14 20:51:07,786 INFO L276 IsEmpty]: Start isEmpty. Operand 0 states and 0 transitions. [2022-02-14 20:51:07,787 INFO L282 IsEmpty]: Finished isEmpty. No accepting run. [2022-02-14 20:51:07,789 INFO L764 garLoopResultBuilder]: Registering result SAFE for location __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION (0 of 1 remaining) [2022-02-14 20:51:07,811 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (6)] Forceful destruction successful, exit code 0 [2022-02-14 20:51:07,999 WARN L452 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable7,6 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2022-02-14 20:51:08,002 INFO L732 BasicCegarLoop]: Path program histogram: [1, 1, 1, 1, 1, 1, 1, 1] [2022-02-14 20:51:08,003 INFO L180 ceAbstractionStarter]: Computing trace abstraction results [2022-02-14 20:51:08,005 INFO L202 PluginConnector]: Adding new model de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction CFG 14.02 08:51:08 BasicIcfg [2022-02-14 20:51:08,005 INFO L132 PluginConnector]: ------------------------ END TraceAbstraction---------------------------- [2022-02-14 20:51:08,005 INFO L158 Benchmark]: Toolchain (without parser) took 6754.42ms. Allocated memory was 178.3MB in the beginning and 276.8MB in the end (delta: 98.6MB). Free memory was 121.4MB in the beginning and 208.7MB in the end (delta: -87.3MB). Peak memory consumption was 12.2MB. Max. memory is 8.0GB. [2022-02-14 20:51:08,005 INFO L158 Benchmark]: CDTParser took 0.11ms. Allocated memory is still 178.3MB. Free memory is still 138.2MB. There was no memory consumed. Max. memory is 8.0GB. [2022-02-14 20:51:08,006 INFO L158 Benchmark]: CACSL2BoogieTranslator took 194.80ms. Allocated memory was 178.3MB in the beginning and 276.8MB in the end (delta: 98.6MB). Free memory was 121.2MB in the beginning and 249.7MB in the end (delta: -128.6MB). Peak memory consumption was 10.4MB. Max. memory is 8.0GB. [2022-02-14 20:51:08,006 INFO L158 Benchmark]: Boogie Preprocessor took 22.85ms. Allocated memory is still 276.8MB. Free memory was 249.7MB in the beginning and 248.2MB in the end (delta: 1.6MB). Peak memory consumption was 2.1MB. Max. memory is 8.0GB. [2022-02-14 20:51:08,006 INFO L158 Benchmark]: RCFGBuilder took 276.37ms. Allocated memory is still 276.8MB. Free memory was 248.2MB in the beginning and 236.1MB in the end (delta: 12.1MB). Peak memory consumption was 11.5MB. Max. memory is 8.0GB. [2022-02-14 20:51:08,006 INFO L158 Benchmark]: IcfgTransformer took 17.24ms. Allocated memory is still 276.8MB. Free memory was 236.1MB in the beginning and 235.1MB in the end (delta: 1.0MB). Peak memory consumption was 1.0MB. Max. memory is 8.0GB. [2022-02-14 20:51:08,007 INFO L158 Benchmark]: TraceAbstraction took 6235.14ms. Allocated memory is still 276.8MB. Free memory was 234.5MB in the beginning and 208.7MB in the end (delta: 25.8MB). Peak memory consumption was 26.4MB. Max. memory is 8.0GB. [2022-02-14 20:51:08,008 INFO L339 ainManager$Toolchain]: ####################### End [Toolchain 1] ####################### --- Results --- * Results from de.uni_freiburg.informatik.ultimate.core: - StatisticsResult: Toolchain Benchmarks Benchmark results are: * CDTParser took 0.11ms. Allocated memory is still 178.3MB. Free memory is still 138.2MB. There was no memory consumed. Max. memory is 8.0GB. * CACSL2BoogieTranslator took 194.80ms. Allocated memory was 178.3MB in the beginning and 276.8MB in the end (delta: 98.6MB). Free memory was 121.2MB in the beginning and 249.7MB in the end (delta: -128.6MB). Peak memory consumption was 10.4MB. Max. memory is 8.0GB. * Boogie Preprocessor took 22.85ms. Allocated memory is still 276.8MB. Free memory was 249.7MB in the beginning and 248.2MB in the end (delta: 1.6MB). Peak memory consumption was 2.1MB. Max. memory is 8.0GB. * RCFGBuilder took 276.37ms. Allocated memory is still 276.8MB. Free memory was 248.2MB in the beginning and 236.1MB in the end (delta: 12.1MB). Peak memory consumption was 11.5MB. Max. memory is 8.0GB. * IcfgTransformer took 17.24ms. Allocated memory is still 276.8MB. Free memory was 236.1MB in the beginning and 235.1MB in the end (delta: 1.0MB). Peak memory consumption was 1.0MB. Max. memory is 8.0GB. * TraceAbstraction took 6235.14ms. Allocated memory is still 276.8MB. Free memory was 234.5MB in the beginning and 208.7MB in the end (delta: 25.8MB). Peak memory consumption was 26.4MB. Max. memory is 8.0GB. * Results from de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction: - StatisticsResult: ErrorAutomatonStatistics NumberErrorTraces: 0, NumberStatementsAllTraces: 0, NumberRelevantStatements: 0, 0.0s ErrorAutomatonConstructionTimeTotal, 0.0s FaulLocalizationTime, NumberStatementsFirstTrace: -1, TraceLengthAvg: 0, 0.0s ErrorAutomatonConstructionTimeAvg, 0.0s ErrorAutomatonDifferenceTimeAvg, 0.0s ErrorAutomatonDifferenceTimeTotal, NumberOfNoEnhancement: 0, NumberOfFiniteEnhancement: 0, NumberOfInfiniteEnhancement: 0 - PositiveResult [Line: 19]: call to reach_error is unreachable For all program executions holds that call to reach_error is unreachable at this location - StatisticsResult: Ultimate Automizer benchmark data CFG has 4 procedures, 30 locations, 1 error locations. Started 1 CEGAR loops. OverallTime: 6.2s, OverallIterations: 8, TraceHistogramMax: 5, PathProgramHistogramMax: 1, EmptinessCheckTime: 0.0s, AutomataDifference: 2.3s, DeadEndRemovalTime: 0.0s, HoareAnnotationTime: 0.0s, InitialAbstractionConstructionTime: 0.0s, PartialOrderReductionTime: 0.0s, HoareTripleCheckerStatistics: 0 mSolverCounterUnknown, 462 SdHoareTripleChecker+Valid, 1.1s IncrementalHoareTripleChecker+Time, 0 mSdLazyCounter, 448 mSDsluCounter, 506 SdHoareTripleChecker+Invalid, 0.9s Time, 0 mProtectedAction, 0 SdHoareTripleChecker+Unchecked, 0 IncrementalHoareTripleChecker+Unchecked, 323 mSDsCounter, 386 IncrementalHoareTripleChecker+Valid, 0 mProtectedPredicate, 1699 IncrementalHoareTripleChecker+Invalid, 2085 SdHoareTripleChecker+Unknown, 0 mSolverCounterNotChecked, 386 mSolverCounterUnsat, 183 mSDtfsCounter, 1699 mSolverCounterSat, 0.0s SdHoareTripleChecker+Time, 0 IncrementalHoareTripleChecker+Unknown, PredicateUnifierStatistics: 0 DeclaredPredicates, 542 GetRequests, 383 SyntacticMatches, 5 SemanticMatches, 154 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 918 ImplicationChecksByTransitivity, 1.4s Time, 0.0s BasicInterpolantAutomatonTime, BiggestAbstraction: size=78occurred in iteration=7, InterpolantAutomatonStates: 100, traceCheckStatistics: No data available, InterpolantConsolidationStatistics: No data available, PathInvariantsStatistics: No data available, 0/0 InterpolantCoveringCapability, TotalInterpolationStatistics: No data available, 0.0s DumpTime, AutomataMinimizationStatistics: 0.1s AutomataMinimizationTime, 8 MinimizatonAttempts, 84 StatesRemovedByMinimization, 5 NontrivialMinimizations, HoareAnnotationStatistics: No data available, RefinementEngineStatistics: TRACE_CHECK: 0.0s SsaConstructionTime, 0.2s SatisfiabilityAnalysisTime, 2.1s InterpolantComputationTime, 450 NumberOfCodeBlocks, 450 NumberOfCodeBlocksAsserted, 13 NumberOfCheckSat, 606 ConstructedInterpolants, 0 QuantifiedInterpolants, 1499 SizeOfPredicates, 21 NumberOfNonLiveVariables, 555 ConjunctsInSsa, 31 ConjunctsInUnsatCore, 17 InterpolantComputations, 4 PerfectInterpolantSequences, 398/439 InterpolantCoveringCapability, INVARIANT_SYNTHESIS: No data available, INTERPOLANT_CONSOLIDATION: No data available, ABSTRACT_INTERPRETATION: No data available, PDR: No data available, ACCELERATED_INTERPOLATION: No data available, SIFA: No data available, ReuseStatistics: No data available - AllSpecificationsHoldResult: All specifications hold 1 specifications checked. All of them hold RESULT: Ultimate proved your program to be correct! [2022-02-14 20:51:08,041 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in -t:2000 (1)] Forceful destruction successful, exit code 0 Received shutdown request...