/usr/lib/jvm/java-1.11.0-openjdk-amd64/bin/java -Xmx8000000000 -Xss4m -jar ./plugins/org.eclipse.equinox.launcher_1.5.800.v20200727-1323.jar -data @noDefault -ultimatedata ./data -s ../../../trunk/examples/settings/default/automizer/svcomp-Reach-32bit-Automizer_Default.epf --cacsl2boogietranslator.use.bitabs.translation true -tc ../../../trunk/examples/toolchains/AutomizerCInline.xml -i ../../../trunk/examples/svcomp/nla-digbench-scaling/cohencu-ll_unwindbound1.c -------------------------------------------------------------------------------- This is Ultimate 0.2.4-tmp.fs.bitabs-eval-d9c3e40-m [2023-12-15 22:09:56,378 INFO L188 SettingsManager]: Resetting all preferences to default values... [2023-12-15 22:09:56,440 INFO L114 SettingsManager]: Loading settings from /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/../../../trunk/examples/settings/default/automizer/svcomp-Reach-32bit-Automizer_Default.epf [2023-12-15 22:09:56,444 WARN L101 SettingsManager]: Preference file contains the following unknown settings: [2023-12-15 22:09:56,445 WARN L103 SettingsManager]: * de.uni_freiburg.informatik.ultimate.core.Log level for class [2023-12-15 22:09:56,472 INFO L130 SettingsManager]: Preferences different from defaults after loading the file: [2023-12-15 22:09:56,472 INFO L151 SettingsManager]: Preferences of UltimateCore differ from their defaults: [2023-12-15 22:09:56,473 INFO L153 SettingsManager]: * Log level for class=de.uni_freiburg.informatik.ultimate.lib.smtlibutils.quantifier.QuantifierPusher=ERROR; [2023-12-15 22:09:56,473 INFO L151 SettingsManager]: Preferences of Boogie Preprocessor differ from their defaults: [2023-12-15 22:09:56,476 INFO L153 SettingsManager]: * Use memory slicer=true [2023-12-15 22:09:56,476 INFO L151 SettingsManager]: Preferences of Boogie Procedure Inliner differ from their defaults: [2023-12-15 22:09:56,477 INFO L153 SettingsManager]: * Ignore calls to procedures called more than once=ONLY_FOR_SEQUENTIAL_PROGRAMS [2023-12-15 22:09:56,477 INFO L151 SettingsManager]: Preferences of BlockEncodingV2 differ from their defaults: [2023-12-15 22:09:56,478 INFO L153 SettingsManager]: * Create parallel compositions if possible=false [2023-12-15 22:09:56,478 INFO L153 SettingsManager]: * Use SBE=true [2023-12-15 22:09:56,478 INFO L151 SettingsManager]: Preferences of CACSL2BoogieTranslator differ from their defaults: [2023-12-15 22:09:56,478 INFO L153 SettingsManager]: * Pointer base address is valid at dereference=IGNORE [2023-12-15 22:09:56,479 INFO L153 SettingsManager]: * sizeof long=4 [2023-12-15 22:09:56,479 INFO L153 SettingsManager]: * Overapproximate operations on floating types=true [2023-12-15 22:09:56,480 INFO L153 SettingsManager]: * sizeof POINTER=4 [2023-12-15 22:09:56,480 INFO L153 SettingsManager]: * Check division by zero=IGNORE [2023-12-15 22:09:56,480 INFO L153 SettingsManager]: * Pointer to allocated memory at dereference=IGNORE [2023-12-15 22:09:56,480 INFO L153 SettingsManager]: * If two pointers are subtracted or compared they have the same base address=IGNORE [2023-12-15 22:09:56,480 INFO L153 SettingsManager]: * Check array bounds for arrays that are off heap=IGNORE [2023-12-15 22:09:56,481 INFO L153 SettingsManager]: * Allow undefined functions=false [2023-12-15 22:09:56,481 INFO L153 SettingsManager]: * sizeof long double=12 [2023-12-15 22:09:56,481 INFO L153 SettingsManager]: * Check if freed pointer was valid=false [2023-12-15 22:09:56,481 INFO L153 SettingsManager]: * Use constant arrays=true [2023-12-15 22:09:56,481 INFO L151 SettingsManager]: Preferences of RCFGBuilder differ from their defaults: [2023-12-15 22:09:56,482 INFO L153 SettingsManager]: * Size of a code block=SequenceOfStatements [2023-12-15 22:09:56,482 INFO L153 SettingsManager]: * Only consider context switches at boundaries of atomic blocks=true [2023-12-15 22:09:56,482 INFO L153 SettingsManager]: * SMT solver=External_DefaultMode [2023-12-15 22:09:56,483 INFO L153 SettingsManager]: * Command for external solver=z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in -t:4000 [2023-12-15 22:09:56,483 INFO L151 SettingsManager]: Preferences of TraceAbstraction differ from their defaults: [2023-12-15 22:09:56,483 INFO L153 SettingsManager]: * Compute Interpolants along a Counterexample=FPandBP [2023-12-15 22:09:56,483 INFO L153 SettingsManager]: * Positions where we compute the Hoare Annotation=LoopHeads [2023-12-15 22:09:56,483 INFO L153 SettingsManager]: * Trace refinement strategy=CAMEL [2023-12-15 22:09:56,483 INFO L153 SettingsManager]: * Command for external solver=z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in [2023-12-15 22:09:56,483 INFO L153 SettingsManager]: * Apply one-shot large block encoding in concurrent analysis=false [2023-12-15 22:09:56,483 INFO L153 SettingsManager]: * Automaton type used in concurrency analysis=PETRI_NET [2023-12-15 22:09:56,483 INFO L153 SettingsManager]: * Compute Hoare Annotation of negated interpolant automaton, abstraction and CFG=true [2023-12-15 22:09:56,484 INFO L153 SettingsManager]: * Order on configurations for Petri net unfoldings=DBO [2023-12-15 22:09:56,484 INFO L153 SettingsManager]: * SMT solver=External_ModelsAndUnsatCoreMode [2023-12-15 22:09:56,484 INFO L153 SettingsManager]: * Looper check in Petri net analysis=SEMANTIC WARNING: An illegal reflective access operation has occurred WARNING: Illegal reflective access by com.sun.xml.bind.v2.runtime.reflect.opt.Injector$1 (file:/storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/plugins/com.sun.xml.bind_2.2.0.v201505121915.jar) to method java.lang.ClassLoader.defineClass(java.lang.String,byte[],int,int) WARNING: Please consider reporting this to the maintainers of com.sun.xml.bind.v2.runtime.reflect.opt.Injector$1 WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations WARNING: All illegal access operations will be denied in a future release Applying setting for plugin de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator: Use bitabs translation -> true [2023-12-15 22:09:56,680 INFO L75 nceAwareModelManager]: Repository-Root is: /tmp [2023-12-15 22:09:56,694 INFO L261 ainManager$Toolchain]: [Toolchain 1]: Applicable parser(s) successfully (re)initialized [2023-12-15 22:09:56,696 INFO L217 ainManager$Toolchain]: [Toolchain 1]: Toolchain selected. [2023-12-15 22:09:56,697 INFO L270 PluginConnector]: Initializing CDTParser... [2023-12-15 22:09:56,699 INFO L274 PluginConnector]: CDTParser initialized [2023-12-15 22:09:56,700 INFO L431 ainManager$Toolchain]: [Toolchain 1]: Parsing single file: /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/../../../trunk/examples/svcomp/nla-digbench-scaling/cohencu-ll_unwindbound1.c [2023-12-15 22:09:57,666 INFO L533 CDTParser]: Created temporary CDT project at NULL [2023-12-15 22:09:57,832 INFO L384 CDTParser]: Found 1 translation units. [2023-12-15 22:09:57,832 INFO L180 CDTParser]: Scanning /storage/repos/ultimate/trunk/examples/svcomp/nla-digbench-scaling/cohencu-ll_unwindbound1.c [2023-12-15 22:09:57,839 INFO L427 CDTParser]: About to delete temporary CDT project at /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/data/ece3a571b/05098e2ff029478594da8a8065c915a2/FLAGc58a90eee [2023-12-15 22:09:57,851 INFO L435 CDTParser]: Successfully deleted /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/data/ece3a571b/05098e2ff029478594da8a8065c915a2 [2023-12-15 22:09:57,853 INFO L299 ainManager$Toolchain]: ####################### [Toolchain 1] ####################### [2023-12-15 22:09:57,855 INFO L133 ToolchainWalker]: Walking toolchain with 5 elements. [2023-12-15 22:09:57,857 INFO L112 PluginConnector]: ------------------------CACSL2BoogieTranslator---------------------------- [2023-12-15 22:09:57,857 INFO L270 PluginConnector]: Initializing CACSL2BoogieTranslator... [2023-12-15 22:09:57,860 INFO L274 PluginConnector]: CACSL2BoogieTranslator initialized [2023-12-15 22:09:57,860 INFO L184 PluginConnector]: Executing the observer ACSLObjectContainerObserver from plugin CACSL2BoogieTranslator for "CDTParser AST 15.12 10:09:57" (1/1) ... [2023-12-15 22:09:57,861 INFO L204 PluginConnector]: Invalid model from CACSL2BoogieTranslator for observer de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator.ACSLObjectContainerObserver@482f8997 and model type de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 15.12 10:09:57, skipping insertion in model container [2023-12-15 22:09:57,861 INFO L184 PluginConnector]: Executing the observer CACSL2BoogieTranslatorObserver from plugin CACSL2BoogieTranslator for "CDTParser AST 15.12 10:09:57" (1/1) ... [2023-12-15 22:09:57,876 INFO L177 MainTranslator]: Built tables and reachable declarations [2023-12-15 22:09:57,970 WARN L239 ndardFunctionHandler]: Function reach_error is already implemented but we override the implementation for the call at /storage/repos/ultimate/trunk/examples/svcomp/nla-digbench-scaling/cohencu-ll_unwindbound1.c[588,601] [2023-12-15 22:09:57,984 INFO L209 PostProcessor]: Analyzing one entry point: main [2023-12-15 22:09:57,990 INFO L202 MainTranslator]: Completed pre-run [2023-12-15 22:09:57,998 WARN L239 ndardFunctionHandler]: Function reach_error is already implemented but we override the implementation for the call at /storage/repos/ultimate/trunk/examples/svcomp/nla-digbench-scaling/cohencu-ll_unwindbound1.c[588,601] [2023-12-15 22:09:58,004 INFO L209 PostProcessor]: Analyzing one entry point: main [2023-12-15 22:09:58,014 INFO L206 MainTranslator]: Completed translation [2023-12-15 22:09:58,014 INFO L201 PluginConnector]: Adding new model de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 15.12 10:09:58 WrapperNode [2023-12-15 22:09:58,015 INFO L131 PluginConnector]: ------------------------ END CACSL2BoogieTranslator---------------------------- [2023-12-15 22:09:58,015 INFO L112 PluginConnector]: ------------------------Boogie Procedure Inliner---------------------------- [2023-12-15 22:09:58,015 INFO L270 PluginConnector]: Initializing Boogie Procedure Inliner... [2023-12-15 22:09:58,015 INFO L274 PluginConnector]: Boogie Procedure Inliner initialized [2023-12-15 22:09:58,020 INFO L184 PluginConnector]: Executing the observer TypeChecker from plugin Boogie Procedure Inliner for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 15.12 10:09:58" (1/1) ... [2023-12-15 22:09:58,024 INFO L184 PluginConnector]: Executing the observer Inliner from plugin Boogie Procedure Inliner for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 15.12 10:09:58" (1/1) ... [2023-12-15 22:09:58,038 INFO L138 Inliner]: procedures = 14, calls = 18, calls flagged for inlining = 2, calls inlined = 2, statements flattened = 49 [2023-12-15 22:09:58,038 INFO L131 PluginConnector]: ------------------------ END Boogie Procedure Inliner---------------------------- [2023-12-15 22:09:58,038 INFO L112 PluginConnector]: ------------------------Boogie Preprocessor---------------------------- [2023-12-15 22:09:58,039 INFO L270 PluginConnector]: Initializing Boogie Preprocessor... [2023-12-15 22:09:58,039 INFO L274 PluginConnector]: Boogie Preprocessor initialized [2023-12-15 22:09:58,045 INFO L184 PluginConnector]: Executing the observer EnsureBoogieModelObserver from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 15.12 10:09:58" (1/1) ... [2023-12-15 22:09:58,045 INFO L184 PluginConnector]: Executing the observer TypeChecker from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 15.12 10:09:58" (1/1) ... [2023-12-15 22:09:58,046 INFO L184 PluginConnector]: Executing the observer MemorySlicer from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 15.12 10:09:58" (1/1) ... [2023-12-15 22:09:58,053 INFO L175 MemorySlicer]: Split 2 memory accesses to 1 slices as follows [2]. 100 percent of accesses are in the largest equivalence class. The 2 initializations are split as follows [2]. The 0 writes are split as follows [0]. [2023-12-15 22:09:58,054 INFO L184 PluginConnector]: Executing the observer ConstExpander from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 15.12 10:09:58" (1/1) ... [2023-12-15 22:09:58,054 INFO L184 PluginConnector]: Executing the observer StructExpander from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 15.12 10:09:58" (1/1) ... [2023-12-15 22:09:58,056 INFO L184 PluginConnector]: Executing the observer UnstructureCode from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 15.12 10:09:58" (1/1) ... [2023-12-15 22:09:58,058 INFO L184 PluginConnector]: Executing the observer FunctionInliner from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 15.12 10:09:58" (1/1) ... [2023-12-15 22:09:58,058 INFO L184 PluginConnector]: Executing the observer LTLStepAnnotator from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 15.12 10:09:58" (1/1) ... [2023-12-15 22:09:58,059 INFO L184 PluginConnector]: Executing the observer BoogieSymbolTableConstructor from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 15.12 10:09:58" (1/1) ... [2023-12-15 22:09:58,061 INFO L131 PluginConnector]: ------------------------ END Boogie Preprocessor---------------------------- [2023-12-15 22:09:58,061 INFO L112 PluginConnector]: ------------------------RCFGBuilder---------------------------- [2023-12-15 22:09:58,061 INFO L270 PluginConnector]: Initializing RCFGBuilder... [2023-12-15 22:09:58,061 INFO L274 PluginConnector]: RCFGBuilder initialized [2023-12-15 22:09:58,062 INFO L184 PluginConnector]: Executing the observer RCFGBuilderObserver from plugin RCFGBuilder for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 15.12 10:09:58" (1/1) ... [2023-12-15 22:09:58,072 INFO L173 SolverBuilder]: Constructing external solver with command: z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in -t:4000 [2023-12-15 22:09:58,080 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-12-15 22:09:58,089 INFO L229 MonitoredProcess]: Starting monitored process 1 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in -t:4000 (exit command is (exit), workingDir is null) [2023-12-15 22:09:58,092 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in -t:4000 (1)] Waiting until timeout for monitored process [2023-12-15 22:09:58,109 INFO L130 BoogieDeclarations]: Found specification of procedure #Ultimate.allocInit [2023-12-15 22:09:58,110 INFO L130 BoogieDeclarations]: Found specification of procedure write~init~int#0 [2023-12-15 22:09:58,110 INFO L130 BoogieDeclarations]: Found specification of procedure ULTIMATE.start [2023-12-15 22:09:58,110 INFO L138 BoogieDeclarations]: Found implementation of procedure ULTIMATE.start [2023-12-15 22:09:58,110 INFO L130 BoogieDeclarations]: Found specification of procedure __VERIFIER_assert [2023-12-15 22:09:58,110 INFO L138 BoogieDeclarations]: Found implementation of procedure __VERIFIER_assert [2023-12-15 22:09:58,151 INFO L241 CfgBuilder]: Building ICFG [2023-12-15 22:09:58,153 INFO L267 CfgBuilder]: Building CFG for each procedure with an implementation [2023-12-15 22:09:58,257 INFO L282 CfgBuilder]: Performing block encoding [2023-12-15 22:09:58,279 INFO L304 CfgBuilder]: Using the 1 location(s) as analysis (start of procedure ULTIMATE.start) [2023-12-15 22:09:58,279 INFO L309 CfgBuilder]: Removed 1 assume(true) statements. [2023-12-15 22:09:58,280 INFO L201 PluginConnector]: Adding new model de.uni_freiburg.informatik.ultimate.plugins.generator.rcfgbuilder CFG 15.12 10:09:58 BoogieIcfgContainer [2023-12-15 22:09:58,280 INFO L131 PluginConnector]: ------------------------ END RCFGBuilder---------------------------- [2023-12-15 22:09:58,281 INFO L112 PluginConnector]: ------------------------TraceAbstraction---------------------------- [2023-12-15 22:09:58,281 INFO L270 PluginConnector]: Initializing TraceAbstraction... [2023-12-15 22:09:58,283 INFO L274 PluginConnector]: TraceAbstraction initialized [2023-12-15 22:09:58,283 INFO L184 PluginConnector]: Executing the observer TraceAbstractionObserver from plugin TraceAbstraction for "CDTParser AST 15.12 10:09:57" (1/3) ... [2023-12-15 22:09:58,284 INFO L204 PluginConnector]: Invalid model from TraceAbstraction for observer de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction.TraceAbstractionObserver@1bbb794b and model type de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction AST 15.12 10:09:58, skipping insertion in model container [2023-12-15 22:09:58,284 INFO L184 PluginConnector]: Executing the observer TraceAbstractionObserver from plugin TraceAbstraction for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 15.12 10:09:58" (2/3) ... [2023-12-15 22:09:58,284 INFO L204 PluginConnector]: Invalid model from TraceAbstraction for observer de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction.TraceAbstractionObserver@1bbb794b and model type de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction AST 15.12 10:09:58, skipping insertion in model container [2023-12-15 22:09:58,284 INFO L184 PluginConnector]: Executing the observer TraceAbstractionObserver from plugin TraceAbstraction for "de.uni_freiburg.informatik.ultimate.plugins.generator.rcfgbuilder CFG 15.12 10:09:58" (3/3) ... [2023-12-15 22:09:58,285 INFO L112 eAbstractionObserver]: Analyzing ICFG cohencu-ll_unwindbound1.c [2023-12-15 22:09:58,295 INFO L204 ceAbstractionStarter]: Automizer settings: Hoare:true NWA Interpolation:FPandBP Determinization: PREDICATE_ABSTRACTION [2023-12-15 22:09:58,295 INFO L163 ceAbstractionStarter]: Applying trace abstraction to program that has 1 error locations. [2023-12-15 22:09:58,322 INFO L356 AbstractCegarLoop]: ======== Iteration 0 == of CEGAR loop == AllErrorsAtOnce ======== [2023-12-15 22:09:58,326 INFO L357 AbstractCegarLoop]: Settings: SEPARATE_VIOLATION_CHECK=true, mInterprocedural=true, mMaxIterations=1000000, mWatchIteration=1000000, mArtifact=RCFG, mInterpolation=FPandBP, mInterpolantAutomaton=STRAIGHT_LINE, mDumpAutomata=false, mAutomataFormat=ATS_NUMERATE, mDumpPath=., mDeterminiation=PREDICATE_ABSTRACTION, mMinimize=MINIMIZE_SEVPA, mHoare=true, mAutomataTypeConcurrency=PETRI_NET, mHoareTripleChecks=INCREMENTAL, mHoareAnnotationPositions=LoopHeads, mDumpOnlyReuseAutomata=false, mLimitTraceHistogram=0, mErrorLocTimeLimit=0, mLimitPathProgramCount=0, mCollectInterpolantStatistics=true, mHeuristicEmptinessCheck=false, mHeuristicEmptinessCheckAStarHeuristic=ZERO, mHeuristicEmptinessCheckAStarHeuristicRandomSeed=1337, mHeuristicEmptinessCheckSmtFeatureScoringMethod=DAGSIZE, mSMTFeatureExtraction=false, mSMTFeatureExtractionDumpPath=., mOverrideInterpolantAutomaton=false, mMcrInterpolantMethod=WP, mPorIndependenceSettings=[Lde.uni_freiburg.informatik.ultimate.lib.tracecheckerutils.partialorder.independence.IndependenceSettings;@1f53fd3f, mLbeIndependenceSettings=[IndependenceType=SEMANTIC, AbstractionType=NONE, UseConditional=false, UseSemiCommutativity=true, Solver=Z3, SolverTimeout=1000ms] [2023-12-15 22:09:58,326 INFO L358 AbstractCegarLoop]: Starting to check reachability of 1 error locations. [2023-12-15 22:09:58,333 INFO L276 IsEmpty]: Start isEmpty. Operand has 23 states, 9 states have (on average 1.5555555555555556) internal successors, (14), 10 states have internal predecessors, (14), 11 states have call successors, (11), 1 states have call predecessors, (11), 1 states have return successors, (11), 11 states have call predecessors, (11), 11 states have call successors, (11) [2023-12-15 22:09:58,337 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 7 [2023-12-15 22:09:58,337 INFO L187 NwaCegarLoop]: Found error trace [2023-12-15 22:09:58,342 INFO L195 NwaCegarLoop]: trace histogram [1, 1, 1, 1, 1, 1] [2023-12-15 22:09:58,343 INFO L420 AbstractCegarLoop]: === Iteration 1 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-12-15 22:09:58,346 INFO L160 PredicateUnifier]: Initialized classic predicate unifier [2023-12-15 22:09:58,346 INFO L85 PathProgramCache]: Analyzing trace with hash -1379524608, now seen corresponding path program 1 times [2023-12-15 22:09:58,351 INFO L118 FreeRefinementEngine]: Executing refinement strategy CAMEL [2023-12-15 22:09:58,352 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1491894372] [2023-12-15 22:09:58,352 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-12-15 22:09:58,352 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-12-15 22:09:58,409 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-12-15 22:09:58,441 INFO L134 CoverageAnalysis]: Checked inductivity of 0 backedges. 0 proven. 0 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2023-12-15 22:09:58,441 INFO L136 FreeRefinementEngine]: Strategy CAMEL found an infeasible trace [2023-12-15 22:09:58,442 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1491894372] [2023-12-15 22:09:58,442 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [1491894372] provided 1 perfect and 0 imperfect interpolant sequences [2023-12-15 22:09:58,442 INFO L185 FreeRefinementEngine]: Found 1 perfect and 0 imperfect interpolant sequences. [2023-12-15 22:09:58,442 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [2] imperfect sequences [] total 2 [2023-12-15 22:09:58,443 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [993569250] [2023-12-15 22:09:58,445 INFO L85 oduleStraightlineAll]: Using 1 perfect interpolants to construct interpolant automaton [2023-12-15 22:09:58,448 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 2 states [2023-12-15 22:09:58,449 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy CAMEL [2023-12-15 22:09:58,468 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 2 interpolants. [2023-12-15 22:09:58,468 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=1, Invalid=1, Unknown=0, NotChecked=0, Total=2 [2023-12-15 22:09:58,470 INFO L87 Difference]: Start difference. First operand has 23 states, 9 states have (on average 1.5555555555555556) internal successors, (14), 10 states have internal predecessors, (14), 11 states have call successors, (11), 1 states have call predecessors, (11), 1 states have return successors, (11), 11 states have call predecessors, (11), 11 states have call successors, (11) Second operand has 2 states, 2 states have (on average 2.5) internal successors, (5), 2 states have internal predecessors, (5), 1 states have call successors, (1), 1 states have call predecessors, (1), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2023-12-15 22:09:58,501 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-12-15 22:09:58,501 INFO L93 Difference]: Finished difference Result 45 states and 82 transitions. [2023-12-15 22:09:58,502 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 2 states. [2023-12-15 22:09:58,502 INFO L78 Accepts]: Start accepts. Automaton has has 2 states, 2 states have (on average 2.5) internal successors, (5), 2 states have internal predecessors, (5), 1 states have call successors, (1), 1 states have call predecessors, (1), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 6 [2023-12-15 22:09:58,503 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-12-15 22:09:58,507 INFO L225 Difference]: With dead ends: 45 [2023-12-15 22:09:58,507 INFO L226 Difference]: Without dead ends: 21 [2023-12-15 22:09:58,509 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 2 GetRequests, 2 SyntacticMatches, 0 SemanticMatches, 0 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 0 ImplicationChecksByTransitivity, 0.0s TimeCoverageRelationStatistics Valid=1, Invalid=1, Unknown=0, NotChecked=0, Total=2 [2023-12-15 22:09:58,511 INFO L413 NwaCegarLoop]: 32 mSDtfsCounter, 0 mSDsluCounter, 0 mSDsCounter, 0 mSdLazyCounter, 2 mSolverCounterSat, 0 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.0s Time, 0 mProtectedPredicate, 0 mProtectedAction, 0 SdHoareTripleChecker+Valid, 32 SdHoareTripleChecker+Invalid, 2 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 0 IncrementalHoareTripleChecker+Valid, 2 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.0s IncrementalHoareTripleChecker+Time [2023-12-15 22:09:58,512 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [0 Valid, 32 Invalid, 2 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [0 Valid, 2 Invalid, 0 Unknown, 0 Unchecked, 0.0s Time] [2023-12-15 22:09:58,521 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 21 states. [2023-12-15 22:09:58,532 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 21 to 21. [2023-12-15 22:09:58,533 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 21 states, 8 states have (on average 1.375) internal successors, (11), 9 states have internal predecessors, (11), 11 states have call successors, (11), 1 states have call predecessors, (11), 1 states have return successors, (10), 10 states have call predecessors, (10), 10 states have call successors, (10) [2023-12-15 22:09:58,533 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 21 states to 21 states and 32 transitions. [2023-12-15 22:09:58,534 INFO L78 Accepts]: Start accepts. Automaton has 21 states and 32 transitions. Word has length 6 [2023-12-15 22:09:58,534 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-12-15 22:09:58,534 INFO L495 AbstractCegarLoop]: Abstraction has 21 states and 32 transitions. [2023-12-15 22:09:58,535 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 2 states, 2 states have (on average 2.5) internal successors, (5), 2 states have internal predecessors, (5), 1 states have call successors, (1), 1 states have call predecessors, (1), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2023-12-15 22:09:58,535 INFO L276 IsEmpty]: Start isEmpty. Operand 21 states and 32 transitions. [2023-12-15 22:09:58,535 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 8 [2023-12-15 22:09:58,535 INFO L187 NwaCegarLoop]: Found error trace [2023-12-15 22:09:58,535 INFO L195 NwaCegarLoop]: trace histogram [1, 1, 1, 1, 1, 1, 1] [2023-12-15 22:09:58,535 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable0 [2023-12-15 22:09:58,536 INFO L420 AbstractCegarLoop]: === Iteration 2 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-12-15 22:09:58,536 INFO L160 PredicateUnifier]: Initialized classic predicate unifier [2023-12-15 22:09:58,536 INFO L85 PathProgramCache]: Analyzing trace with hash -345068235, now seen corresponding path program 1 times [2023-12-15 22:09:58,536 INFO L118 FreeRefinementEngine]: Executing refinement strategy CAMEL [2023-12-15 22:09:58,537 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [566467440] [2023-12-15 22:09:58,537 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-12-15 22:09:58,537 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-12-15 22:09:58,548 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-12-15 22:09:58,604 INFO L134 CoverageAnalysis]: Checked inductivity of 0 backedges. 0 proven. 0 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2023-12-15 22:09:58,605 INFO L136 FreeRefinementEngine]: Strategy CAMEL found an infeasible trace [2023-12-15 22:09:58,605 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [566467440] [2023-12-15 22:09:58,605 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [566467440] provided 1 perfect and 0 imperfect interpolant sequences [2023-12-15 22:09:58,605 INFO L185 FreeRefinementEngine]: Found 1 perfect and 0 imperfect interpolant sequences. [2023-12-15 22:09:58,605 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [3] imperfect sequences [] total 3 [2023-12-15 22:09:58,605 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1984078818] [2023-12-15 22:09:58,605 INFO L85 oduleStraightlineAll]: Using 1 perfect interpolants to construct interpolant automaton [2023-12-15 22:09:58,606 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 4 states [2023-12-15 22:09:58,606 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy CAMEL [2023-12-15 22:09:58,607 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 4 interpolants. [2023-12-15 22:09:58,607 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=5, Invalid=7, Unknown=0, NotChecked=0, Total=12 [2023-12-15 22:09:58,607 INFO L87 Difference]: Start difference. First operand 21 states and 32 transitions. Second operand has 4 states, 4 states have (on average 1.5) internal successors, (6), 3 states have internal predecessors, (6), 1 states have call successors, (1), 1 states have call predecessors, (1), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2023-12-15 22:09:58,634 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-12-15 22:09:58,635 INFO L93 Difference]: Finished difference Result 35 states and 51 transitions. [2023-12-15 22:09:58,635 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 4 states. [2023-12-15 22:09:58,635 INFO L78 Accepts]: Start accepts. Automaton has has 4 states, 4 states have (on average 1.5) internal successors, (6), 3 states have internal predecessors, (6), 1 states have call successors, (1), 1 states have call predecessors, (1), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 7 [2023-12-15 22:09:58,635 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-12-15 22:09:58,636 INFO L225 Difference]: With dead ends: 35 [2023-12-15 22:09:58,636 INFO L226 Difference]: Without dead ends: 23 [2023-12-15 22:09:58,636 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 3 GetRequests, 1 SyntacticMatches, 0 SemanticMatches, 2 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 0 ImplicationChecksByTransitivity, 0.0s TimeCoverageRelationStatistics Valid=5, Invalid=7, Unknown=0, NotChecked=0, Total=12 [2023-12-15 22:09:58,637 INFO L413 NwaCegarLoop]: 29 mSDtfsCounter, 0 mSDsluCounter, 57 mSDsCounter, 0 mSdLazyCounter, 9 mSolverCounterSat, 0 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.0s Time, 0 mProtectedPredicate, 0 mProtectedAction, 0 SdHoareTripleChecker+Valid, 86 SdHoareTripleChecker+Invalid, 9 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 0 IncrementalHoareTripleChecker+Valid, 9 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.0s IncrementalHoareTripleChecker+Time [2023-12-15 22:09:58,638 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [0 Valid, 86 Invalid, 9 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [0 Valid, 9 Invalid, 0 Unknown, 0 Unchecked, 0.0s Time] [2023-12-15 22:09:58,638 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 23 states. [2023-12-15 22:09:58,642 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 23 to 23. [2023-12-15 22:09:58,643 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 23 states, 10 states have (on average 1.3) internal successors, (13), 11 states have internal predecessors, (13), 11 states have call successors, (11), 1 states have call predecessors, (11), 1 states have return successors, (10), 10 states have call predecessors, (10), 10 states have call successors, (10) [2023-12-15 22:09:58,643 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 23 states to 23 states and 34 transitions. [2023-12-15 22:09:58,644 INFO L78 Accepts]: Start accepts. Automaton has 23 states and 34 transitions. Word has length 7 [2023-12-15 22:09:58,644 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-12-15 22:09:58,644 INFO L495 AbstractCegarLoop]: Abstraction has 23 states and 34 transitions. [2023-12-15 22:09:58,644 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 4 states, 4 states have (on average 1.5) internal successors, (6), 3 states have internal predecessors, (6), 1 states have call successors, (1), 1 states have call predecessors, (1), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2023-12-15 22:09:58,644 INFO L276 IsEmpty]: Start isEmpty. Operand 23 states and 34 transitions. [2023-12-15 22:09:58,644 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 8 [2023-12-15 22:09:58,644 INFO L187 NwaCegarLoop]: Found error trace [2023-12-15 22:09:58,644 INFO L195 NwaCegarLoop]: trace histogram [1, 1, 1, 1, 1, 1, 1] [2023-12-15 22:09:58,645 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable1 [2023-12-15 22:09:58,645 INFO L420 AbstractCegarLoop]: === Iteration 3 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-12-15 22:09:58,645 INFO L160 PredicateUnifier]: Initialized classic predicate unifier [2023-12-15 22:09:58,645 INFO L85 PathProgramCache]: Analyzing trace with hash -343519103, now seen corresponding path program 1 times [2023-12-15 22:09:58,645 INFO L118 FreeRefinementEngine]: Executing refinement strategy CAMEL [2023-12-15 22:09:58,646 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [41576165] [2023-12-15 22:09:58,646 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-12-15 22:09:58,646 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-12-15 22:09:58,654 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-12-15 22:09:58,822 INFO L134 CoverageAnalysis]: Checked inductivity of 0 backedges. 0 proven. 0 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2023-12-15 22:09:58,822 INFO L136 FreeRefinementEngine]: Strategy CAMEL found an infeasible trace [2023-12-15 22:09:58,822 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [41576165] [2023-12-15 22:09:58,822 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleSmtInterpolCraig [41576165] provided 1 perfect and 0 imperfect interpolant sequences [2023-12-15 22:09:58,822 INFO L185 FreeRefinementEngine]: Found 1 perfect and 0 imperfect interpolant sequences. [2023-12-15 22:09:58,822 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [4] imperfect sequences [] total 4 [2023-12-15 22:09:58,823 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1631815959] [2023-12-15 22:09:58,823 INFO L85 oduleStraightlineAll]: Using 1 perfect interpolants to construct interpolant automaton [2023-12-15 22:09:58,823 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 5 states [2023-12-15 22:09:58,823 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy CAMEL [2023-12-15 22:09:58,823 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 5 interpolants. [2023-12-15 22:09:58,824 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=7, Invalid=13, Unknown=0, NotChecked=0, Total=20 [2023-12-15 22:09:58,824 INFO L87 Difference]: Start difference. First operand 23 states and 34 transitions. Second operand has 5 states, 5 states have (on average 1.2) internal successors, (6), 3 states have internal predecessors, (6), 1 states have call successors, (1), 1 states have call predecessors, (1), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2023-12-15 22:09:58,894 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-12-15 22:09:58,895 INFO L93 Difference]: Finished difference Result 29 states and 39 transitions. [2023-12-15 22:09:58,895 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 6 states. [2023-12-15 22:09:58,895 INFO L78 Accepts]: Start accepts. Automaton has has 5 states, 5 states have (on average 1.2) internal successors, (6), 3 states have internal predecessors, (6), 1 states have call successors, (1), 1 states have call predecessors, (1), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) Word has length 7 [2023-12-15 22:09:58,895 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-12-15 22:09:58,896 INFO L225 Difference]: With dead ends: 29 [2023-12-15 22:09:58,896 INFO L226 Difference]: Without dead ends: 27 [2023-12-15 22:09:58,896 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 5 GetRequests, 1 SyntacticMatches, 0 SemanticMatches, 4 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 0 ImplicationChecksByTransitivity, 0.0s TimeCoverageRelationStatistics Valid=11, Invalid=19, Unknown=0, NotChecked=0, Total=30 [2023-12-15 22:09:58,897 INFO L413 NwaCegarLoop]: 25 mSDtfsCounter, 8 mSDsluCounter, 52 mSDsCounter, 0 mSdLazyCounter, 31 mSolverCounterSat, 3 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.0s Time, 0 mProtectedPredicate, 0 mProtectedAction, 18 SdHoareTripleChecker+Valid, 77 SdHoareTripleChecker+Invalid, 34 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 3 IncrementalHoareTripleChecker+Valid, 31 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.0s IncrementalHoareTripleChecker+Time [2023-12-15 22:09:58,897 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [18 Valid, 77 Invalid, 34 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [3 Valid, 31 Invalid, 0 Unknown, 0 Unchecked, 0.0s Time] [2023-12-15 22:09:58,898 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 27 states. [2023-12-15 22:09:58,904 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 27 to 27. [2023-12-15 22:09:58,904 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 27 states, 13 states have (on average 1.2307692307692308) internal successors, (16), 14 states have internal predecessors, (16), 11 states have call successors, (11), 2 states have call predecessors, (11), 2 states have return successors, (10), 10 states have call predecessors, (10), 10 states have call successors, (10) [2023-12-15 22:09:58,905 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 27 states to 27 states and 37 transitions. [2023-12-15 22:09:58,905 INFO L78 Accepts]: Start accepts. Automaton has 27 states and 37 transitions. Word has length 7 [2023-12-15 22:09:58,906 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-12-15 22:09:58,906 INFO L495 AbstractCegarLoop]: Abstraction has 27 states and 37 transitions. [2023-12-15 22:09:58,906 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 5 states, 5 states have (on average 1.2) internal successors, (6), 3 states have internal predecessors, (6), 1 states have call successors, (1), 1 states have call predecessors, (1), 0 states have return successors, (0), 0 states have call predecessors, (0), 0 states have call successors, (0) [2023-12-15 22:09:58,906 INFO L276 IsEmpty]: Start isEmpty. Operand 27 states and 37 transitions. [2023-12-15 22:09:58,906 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 13 [2023-12-15 22:09:58,906 INFO L187 NwaCegarLoop]: Found error trace [2023-12-15 22:09:58,906 INFO L195 NwaCegarLoop]: trace histogram [2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-12-15 22:09:58,906 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable2 [2023-12-15 22:09:58,907 INFO L420 AbstractCegarLoop]: === Iteration 4 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-12-15 22:09:58,907 INFO L160 PredicateUnifier]: Initialized classic predicate unifier [2023-12-15 22:09:58,907 INFO L85 PathProgramCache]: Analyzing trace with hash -875596316, now seen corresponding path program 1 times [2023-12-15 22:09:58,907 INFO L118 FreeRefinementEngine]: Executing refinement strategy CAMEL [2023-12-15 22:09:58,907 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [397513009] [2023-12-15 22:09:58,907 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-12-15 22:09:58,907 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-12-15 22:09:58,928 ERROR L246 FreeRefinementEngine]: Caught known exception: Unsupported non-linear arithmetic [2023-12-15 22:09:58,928 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleZ3 [1334458612] [2023-12-15 22:09:58,928 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-12-15 22:09:58,928 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-12-15 22:09:58,928 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-12-15 22:09:58,932 INFO L229 MonitoredProcess]: Starting monitored process 2 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-12-15 22:09:58,948 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (2)] Waiting until timeout for monitored process [2023-12-15 22:09:58,979 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-12-15 22:09:58,980 INFO L262 TraceCheckSpWp]: Trace formula consists of 56 conjuncts, 17 conjunts are in the unsatisfiable core [2023-12-15 22:09:58,983 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-12-15 22:09:59,105 INFO L134 CoverageAnalysis]: Checked inductivity of 2 backedges. 1 proven. 1 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2023-12-15 22:09:59,105 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-12-15 22:09:59,251 INFO L134 CoverageAnalysis]: Checked inductivity of 2 backedges. 1 proven. 1 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2023-12-15 22:09:59,251 INFO L136 FreeRefinementEngine]: Strategy CAMEL found an infeasible trace [2023-12-15 22:09:59,252 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [397513009] [2023-12-15 22:09:59,252 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: SMT_SOLVER_CANNOT_INTERPOLATE_INPUT [2023-12-15 22:09:59,252 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1334458612] [2023-12-15 22:09:59,255 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1334458612] provided 0 perfect and 2 imperfect interpolant sequences [2023-12-15 22:09:59,255 INFO L185 FreeRefinementEngine]: Found 0 perfect and 2 imperfect interpolant sequences. [2023-12-15 22:09:59,256 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [8, 7] total 12 [2023-12-15 22:09:59,256 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1116543219] [2023-12-15 22:09:59,256 INFO L85 oduleStraightlineAll]: Using 2 imperfect interpolants to construct interpolant automaton [2023-12-15 22:09:59,256 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 12 states [2023-12-15 22:09:59,257 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy CAMEL [2023-12-15 22:09:59,258 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 12 interpolants. [2023-12-15 22:09:59,259 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=32, Invalid=100, Unknown=0, NotChecked=0, Total=132 [2023-12-15 22:09:59,260 INFO L87 Difference]: Start difference. First operand 27 states and 37 transitions. Second operand has 12 states, 10 states have (on average 1.6) internal successors, (16), 8 states have internal predecessors, (16), 4 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) [2023-12-15 22:09:59,516 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-12-15 22:09:59,516 INFO L93 Difference]: Finished difference Result 53 states and 75 transitions. [2023-12-15 22:09:59,516 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 9 states. [2023-12-15 22:09:59,516 INFO L78 Accepts]: Start accepts. Automaton has has 12 states, 10 states have (on average 1.6) internal successors, (16), 8 states have internal predecessors, (16), 4 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 12 [2023-12-15 22:09:59,517 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-12-15 22:09:59,518 INFO L225 Difference]: With dead ends: 53 [2023-12-15 22:09:59,518 INFO L226 Difference]: Without dead ends: 51 [2023-12-15 22:09:59,519 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 24 GetRequests, 12 SyntacticMatches, 0 SemanticMatches, 12 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 16 ImplicationChecksByTransitivity, 0.1s TimeCoverageRelationStatistics Valid=47, Invalid=135, Unknown=0, NotChecked=0, Total=182 [2023-12-15 22:09:59,519 INFO L413 NwaCegarLoop]: 21 mSDtfsCounter, 26 mSDsluCounter, 53 mSDsCounter, 0 mSdLazyCounter, 110 mSolverCounterSat, 34 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.2s Time, 0 mProtectedPredicate, 0 mProtectedAction, 46 SdHoareTripleChecker+Valid, 74 SdHoareTripleChecker+Invalid, 144 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 34 IncrementalHoareTripleChecker+Valid, 110 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.2s IncrementalHoareTripleChecker+Time [2023-12-15 22:09:59,520 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [46 Valid, 74 Invalid, 144 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [34 Valid, 110 Invalid, 0 Unknown, 0 Unchecked, 0.2s Time] [2023-12-15 22:09:59,520 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 51 states. [2023-12-15 22:09:59,531 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 51 to 46. [2023-12-15 22:09:59,531 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 46 states, 20 states have (on average 1.2) internal successors, (24), 22 states have internal predecessors, (24), 21 states have call successors, (21), 4 states have call predecessors, (21), 4 states have return successors, (20), 19 states have call predecessors, (20), 20 states have call successors, (20) [2023-12-15 22:09:59,532 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 46 states to 46 states and 65 transitions. [2023-12-15 22:09:59,532 INFO L78 Accepts]: Start accepts. Automaton has 46 states and 65 transitions. Word has length 12 [2023-12-15 22:09:59,533 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-12-15 22:09:59,533 INFO L495 AbstractCegarLoop]: Abstraction has 46 states and 65 transitions. [2023-12-15 22:09:59,533 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 12 states, 10 states have (on average 1.6) internal successors, (16), 8 states have internal predecessors, (16), 4 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) [2023-12-15 22:09:59,533 INFO L276 IsEmpty]: Start isEmpty. Operand 46 states and 65 transitions. [2023-12-15 22:09:59,533 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 18 [2023-12-15 22:09:59,533 INFO L187 NwaCegarLoop]: Found error trace [2023-12-15 22:09:59,533 INFO L195 NwaCegarLoop]: trace histogram [3, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-12-15 22:09:59,541 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (2)] Forceful destruction successful, exit code 0 [2023-12-15 22:09:59,738 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable3,2 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-12-15 22:09:59,738 INFO L420 AbstractCegarLoop]: === Iteration 5 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-12-15 22:09:59,739 INFO L160 PredicateUnifier]: Initialized classic predicate unifier [2023-12-15 22:09:59,739 INFO L85 PathProgramCache]: Analyzing trace with hash 2105691681, now seen corresponding path program 1 times [2023-12-15 22:09:59,739 INFO L118 FreeRefinementEngine]: Executing refinement strategy CAMEL [2023-12-15 22:09:59,739 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1240753437] [2023-12-15 22:09:59,739 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-12-15 22:09:59,739 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-12-15 22:09:59,752 ERROR L246 FreeRefinementEngine]: Caught known exception: Unsupported non-linear arithmetic [2023-12-15 22:09:59,753 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleZ3 [1259695940] [2023-12-15 22:09:59,753 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-12-15 22:09:59,753 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-12-15 22:09:59,753 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-12-15 22:09:59,768 INFO L229 MonitoredProcess]: Starting monitored process 3 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-12-15 22:09:59,776 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (3)] Waiting until timeout for monitored process [2023-12-15 22:09:59,798 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-12-15 22:09:59,799 INFO L262 TraceCheckSpWp]: Trace formula consists of 65 conjuncts, 17 conjunts are in the unsatisfiable core [2023-12-15 22:09:59,800 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-12-15 22:09:59,867 INFO L134 CoverageAnalysis]: Checked inductivity of 8 backedges. 3 proven. 4 refuted. 0 times theorem prover too weak. 1 trivial. 0 not checked. [2023-12-15 22:09:59,867 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-12-15 22:09:59,951 INFO L134 CoverageAnalysis]: Checked inductivity of 8 backedges. 3 proven. 4 refuted. 0 times theorem prover too weak. 1 trivial. 0 not checked. [2023-12-15 22:09:59,952 INFO L136 FreeRefinementEngine]: Strategy CAMEL found an infeasible trace [2023-12-15 22:09:59,954 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [1240753437] [2023-12-15 22:09:59,954 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: SMT_SOLVER_CANNOT_INTERPOLATE_INPUT [2023-12-15 22:09:59,954 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1259695940] [2023-12-15 22:09:59,954 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1259695940] provided 0 perfect and 2 imperfect interpolant sequences [2023-12-15 22:09:59,954 INFO L185 FreeRefinementEngine]: Found 0 perfect and 2 imperfect interpolant sequences. [2023-12-15 22:09:59,954 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [8, 7] total 12 [2023-12-15 22:09:59,955 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [89032490] [2023-12-15 22:09:59,955 INFO L85 oduleStraightlineAll]: Using 2 imperfect interpolants to construct interpolant automaton [2023-12-15 22:09:59,955 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 12 states [2023-12-15 22:09:59,955 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy CAMEL [2023-12-15 22:09:59,956 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 12 interpolants. [2023-12-15 22:09:59,956 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=32, Invalid=100, Unknown=0, NotChecked=0, Total=132 [2023-12-15 22:09:59,956 INFO L87 Difference]: Start difference. First operand 46 states and 65 transitions. Second operand has 12 states, 10 states have (on average 1.9) internal successors, (19), 9 states have internal predecessors, (19), 4 states have call successors, (6), 3 states have call predecessors, (6), 2 states have return successors, (4), 2 states have call predecessors, (4), 4 states have call successors, (4) [2023-12-15 22:10:00,234 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-12-15 22:10:00,234 INFO L93 Difference]: Finished difference Result 59 states and 82 transitions. [2023-12-15 22:10:00,234 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 8 states. [2023-12-15 22:10:00,235 INFO L78 Accepts]: Start accepts. Automaton has has 12 states, 10 states have (on average 1.9) internal successors, (19), 9 states have internal predecessors, (19), 4 states have call successors, (6), 3 states have call predecessors, (6), 2 states have return successors, (4), 2 states have call predecessors, (4), 4 states have call successors, (4) Word has length 17 [2023-12-15 22:10:00,235 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-12-15 22:10:00,235 INFO L225 Difference]: With dead ends: 59 [2023-12-15 22:10:00,235 INFO L226 Difference]: Without dead ends: 57 [2023-12-15 22:10:00,236 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 34 GetRequests, 22 SyntacticMatches, 0 SemanticMatches, 12 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 16 ImplicationChecksByTransitivity, 0.1s TimeCoverageRelationStatistics Valid=47, Invalid=135, Unknown=0, NotChecked=0, Total=182 [2023-12-15 22:10:00,236 INFO L413 NwaCegarLoop]: 21 mSDtfsCounter, 19 mSDsluCounter, 74 mSDsCounter, 0 mSdLazyCounter, 205 mSolverCounterSat, 29 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.2s Time, 0 mProtectedPredicate, 0 mProtectedAction, 36 SdHoareTripleChecker+Valid, 95 SdHoareTripleChecker+Invalid, 234 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 29 IncrementalHoareTripleChecker+Valid, 205 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.2s IncrementalHoareTripleChecker+Time [2023-12-15 22:10:00,236 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [36 Valid, 95 Invalid, 234 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [29 Valid, 205 Invalid, 0 Unknown, 0 Unchecked, 0.2s Time] [2023-12-15 22:10:00,237 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 57 states. [2023-12-15 22:10:00,246 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 57 to 50. [2023-12-15 22:10:00,246 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 50 states, 23 states have (on average 1.173913043478261) internal successors, (27), 25 states have internal predecessors, (27), 21 states have call successors, (21), 5 states have call predecessors, (21), 5 states have return successors, (20), 19 states have call predecessors, (20), 20 states have call successors, (20) [2023-12-15 22:10:00,247 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 50 states to 50 states and 68 transitions. [2023-12-15 22:10:00,247 INFO L78 Accepts]: Start accepts. Automaton has 50 states and 68 transitions. Word has length 17 [2023-12-15 22:10:00,247 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-12-15 22:10:00,247 INFO L495 AbstractCegarLoop]: Abstraction has 50 states and 68 transitions. [2023-12-15 22:10:00,248 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 12 states, 10 states have (on average 1.9) internal successors, (19), 9 states have internal predecessors, (19), 4 states have call successors, (6), 3 states have call predecessors, (6), 2 states have return successors, (4), 2 states have call predecessors, (4), 4 states have call successors, (4) [2023-12-15 22:10:00,248 INFO L276 IsEmpty]: Start isEmpty. Operand 50 states and 68 transitions. [2023-12-15 22:10:00,248 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 23 [2023-12-15 22:10:00,248 INFO L187 NwaCegarLoop]: Found error trace [2023-12-15 22:10:00,248 INFO L195 NwaCegarLoop]: trace histogram [4, 3, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-12-15 22:10:00,260 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (3)] Forceful destruction successful, exit code 0 [2023-12-15 22:10:00,448 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable4,3 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-12-15 22:10:00,451 INFO L420 AbstractCegarLoop]: === Iteration 6 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-12-15 22:10:00,451 INFO L160 PredicateUnifier]: Initialized classic predicate unifier [2023-12-15 22:10:00,452 INFO L85 PathProgramCache]: Analyzing trace with hash 168504260, now seen corresponding path program 1 times [2023-12-15 22:10:00,452 INFO L118 FreeRefinementEngine]: Executing refinement strategy CAMEL [2023-12-15 22:10:00,452 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [2127383835] [2023-12-15 22:10:00,452 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-12-15 22:10:00,452 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-12-15 22:10:00,458 ERROR L246 FreeRefinementEngine]: Caught known exception: Unsupported non-linear arithmetic [2023-12-15 22:10:00,458 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleZ3 [1726360115] [2023-12-15 22:10:00,458 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-12-15 22:10:00,458 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-12-15 22:10:00,458 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-12-15 22:10:00,459 INFO L229 MonitoredProcess]: Starting monitored process 4 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-12-15 22:10:00,483 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (4)] Waiting until timeout for monitored process [2023-12-15 22:10:00,490 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2023-12-15 22:10:00,490 INFO L262 TraceCheckSpWp]: Trace formula consists of 74 conjuncts, 19 conjunts are in the unsatisfiable core [2023-12-15 22:10:00,492 INFO L285 TraceCheckSpWp]: Computing forward predicates... [2023-12-15 22:10:00,553 INFO L134 CoverageAnalysis]: Checked inductivity of 18 backedges. 5 proven. 7 refuted. 0 times theorem prover too weak. 6 trivial. 0 not checked. [2023-12-15 22:10:00,553 INFO L327 TraceCheckSpWp]: Computing backward predicates... [2023-12-15 22:10:00,951 INFO L134 CoverageAnalysis]: Checked inductivity of 18 backedges. 5 proven. 7 refuted. 0 times theorem prover too weak. 6 trivial. 0 not checked. [2023-12-15 22:10:00,951 INFO L136 FreeRefinementEngine]: Strategy CAMEL found an infeasible trace [2023-12-15 22:10:00,951 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleSmtInterpolCraig [2127383835] [2023-12-15 22:10:00,951 WARN L311 FreeRefinementEngine]: Interpolation failed due to KNOWN_IGNORE: SMT_SOLVER_CANNOT_INTERPOLATE_INPUT [2023-12-15 22:10:00,951 INFO L334 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModuleZ3 [1726360115] [2023-12-15 22:10:00,951 INFO L158 FreeRefinementEngine]: IpTcStrategyModuleZ3 [1726360115] provided 0 perfect and 2 imperfect interpolant sequences [2023-12-15 22:10:00,952 INFO L185 FreeRefinementEngine]: Found 0 perfect and 2 imperfect interpolant sequences. [2023-12-15 22:10:00,952 INFO L198 FreeRefinementEngine]: Number of different interpolants: perfect sequences [] imperfect sequences [8, 7] total 12 [2023-12-15 22:10:00,952 INFO L121 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [19351677] [2023-12-15 22:10:00,952 INFO L85 oduleStraightlineAll]: Using 2 imperfect interpolants to construct interpolant automaton [2023-12-15 22:10:00,952 INFO L571 AbstractCegarLoop]: INTERPOLANT automaton has 12 states [2023-12-15 22:10:00,952 INFO L100 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy CAMEL [2023-12-15 22:10:00,953 INFO L143 InterpolantAutomaton]: Constructing interpolant automaton starting with 12 interpolants. [2023-12-15 22:10:00,953 INFO L145 InterpolantAutomaton]: CoverageRelationStatistics Valid=32, Invalid=100, Unknown=0, NotChecked=0, Total=132 [2023-12-15 22:10:00,953 INFO L87 Difference]: Start difference. First operand 50 states and 68 transitions. Second operand has 12 states, 10 states have (on average 1.9) internal successors, (19), 9 states have internal predecessors, (19), 4 states have call successors, (8), 3 states have call predecessors, (8), 2 states have return successors, (6), 2 states have call predecessors, (6), 4 states have call successors, (6) [2023-12-15 22:10:01,368 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2023-12-15 22:10:01,368 INFO L93 Difference]: Finished difference Result 73 states and 99 transitions. [2023-12-15 22:10:01,368 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 8 states. [2023-12-15 22:10:01,369 INFO L78 Accepts]: Start accepts. Automaton has has 12 states, 10 states have (on average 1.9) internal successors, (19), 9 states have internal predecessors, (19), 4 states have call successors, (8), 3 states have call predecessors, (8), 2 states have return successors, (6), 2 states have call predecessors, (6), 4 states have call successors, (6) Word has length 22 [2023-12-15 22:10:01,369 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2023-12-15 22:10:01,369 INFO L225 Difference]: With dead ends: 73 [2023-12-15 22:10:01,369 INFO L226 Difference]: Without dead ends: 64 [2023-12-15 22:10:01,370 INFO L412 NwaCegarLoop]: 0 DeclaredPredicates, 44 GetRequests, 32 SyntacticMatches, 0 SemanticMatches, 12 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 16 ImplicationChecksByTransitivity, 0.1s TimeCoverageRelationStatistics Valid=47, Invalid=135, Unknown=0, NotChecked=0, Total=182 [2023-12-15 22:10:01,370 INFO L413 NwaCegarLoop]: 21 mSDtfsCounter, 21 mSDsluCounter, 96 mSDsCounter, 0 mSdLazyCounter, 175 mSolverCounterSat, 23 mSolverCounterUnsat, 0 mSolverCounterUnknown, 0 mSolverCounterNotChecked, 0.4s Time, 0 mProtectedPredicate, 0 mProtectedAction, 38 SdHoareTripleChecker+Valid, 117 SdHoareTripleChecker+Invalid, 198 SdHoareTripleChecker+Unknown, 0 SdHoareTripleChecker+Unchecked, 0.0s SdHoareTripleChecker+Time, 23 IncrementalHoareTripleChecker+Valid, 175 IncrementalHoareTripleChecker+Invalid, 0 IncrementalHoareTripleChecker+Unknown, 0 IncrementalHoareTripleChecker+Unchecked, 0.4s IncrementalHoareTripleChecker+Time [2023-12-15 22:10:01,370 INFO L414 NwaCegarLoop]: SdHoareTripleChecker [38 Valid, 117 Invalid, 198 Unknown, 0 Unchecked, 0.0s Time], IncrementalHoareTripleChecker [23 Valid, 175 Invalid, 0 Unknown, 0 Unchecked, 0.4s Time] [2023-12-15 22:10:01,371 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 64 states. [2023-12-15 22:10:01,382 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 64 to 64. [2023-12-15 22:10:01,382 INFO L82 GeneralOperation]: Start removeUnreachable. Operand has 64 states, 31 states have (on average 1.1290322580645162) internal successors, (35), 34 states have internal predecessors, (35), 25 states have call successors, (25), 7 states have call predecessors, (25), 7 states have return successors, (23), 22 states have call predecessors, (23), 23 states have call successors, (23) [2023-12-15 22:10:01,383 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 64 states to 64 states and 83 transitions. [2023-12-15 22:10:01,383 INFO L78 Accepts]: Start accepts. Automaton has 64 states and 83 transitions. Word has length 22 [2023-12-15 22:10:01,383 INFO L84 Accepts]: Finished accepts. word is rejected. [2023-12-15 22:10:01,383 INFO L495 AbstractCegarLoop]: Abstraction has 64 states and 83 transitions. [2023-12-15 22:10:01,383 INFO L496 AbstractCegarLoop]: INTERPOLANT automaton has has 12 states, 10 states have (on average 1.9) internal successors, (19), 9 states have internal predecessors, (19), 4 states have call successors, (8), 3 states have call predecessors, (8), 2 states have return successors, (6), 2 states have call predecessors, (6), 4 states have call successors, (6) [2023-12-15 22:10:01,383 INFO L276 IsEmpty]: Start isEmpty. Operand 64 states and 83 transitions. [2023-12-15 22:10:01,384 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 41 [2023-12-15 22:10:01,384 INFO L187 NwaCegarLoop]: Found error trace [2023-12-15 22:10:01,384 INFO L195 NwaCegarLoop]: trace histogram [7, 6, 6, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2023-12-15 22:10:01,390 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (4)] Forceful destruction successful, exit code 0 [2023-12-15 22:10:01,588 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable5,4 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-12-15 22:10:01,589 INFO L420 AbstractCegarLoop]: === Iteration 7 === Targeting __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION === [__VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION] === [2023-12-15 22:10:01,589 INFO L160 PredicateUnifier]: Initialized classic predicate unifier [2023-12-15 22:10:01,589 INFO L85 PathProgramCache]: Analyzing trace with hash 1666200982, now seen corresponding path program 1 times [2023-12-15 22:10:01,589 INFO L118 FreeRefinementEngine]: Executing refinement strategy CAMEL [2023-12-15 22:10:01,589 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleSmtInterpolCraig [1313625786] [2023-12-15 22:10:01,589 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-12-15 22:10:01,589 INFO L127 SolverBuilder]: Constructing new instance of SMTInterpol with explicit timeout -1 ms and remaining time -1 ms [2023-12-15 22:10:01,596 ERROR L246 FreeRefinementEngine]: Caught known exception: Unsupported non-linear arithmetic [2023-12-15 22:10:01,596 INFO L334 FreeRefinementEngine]: Using trace check IpTcStrategyModuleZ3 [753466251] [2023-12-15 22:10:01,596 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2023-12-15 22:10:01,596 INFO L173 SolverBuilder]: Constructing external solver with command: z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-12-15 22:10:01,596 INFO L189 MonitoredProcess]: No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 [2023-12-15 22:10:01,597 INFO L229 MonitoredProcess]: Starting monitored process 5 with /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (exit command is (exit), workingDir is null) [2023-12-15 22:10:01,599 INFO L327 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (5)] Waiting until timeout for monitored process [2023-12-15 22:10:01,634 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is sat [2023-12-15 22:10:01,634 INFO L356 TraceCheck]: Trace is feasible, we will do another trace check, this time with branch encoders. [2023-12-15 22:10:01,645 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is sat [2023-12-15 22:10:01,658 INFO L130 FreeRefinementEngine]: Strategy CAMEL found a feasible trace [2023-12-15 22:10:01,658 INFO L360 BasicCegarLoop]: Counterexample is feasible [2023-12-15 22:10:01,658 INFO L805 garLoopResultBuilder]: Registering result UNSAFE for location __VERIFIER_assertErr0ASSERT_VIOLATIONERROR_FUNCTION (0 of 1 remaining) [2023-12-15 22:10:01,667 INFO L540 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true (5)] Forceful destruction successful, exit code 0 [2023-12-15 22:10:01,865 WARN L477 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable6,5 /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 -smt2 -in SMTLIB2_COMPLIANT=true [2023-12-15 22:10:01,868 INFO L445 BasicCegarLoop]: Path program histogram: [1, 1, 1, 1, 1, 1, 1] [2023-12-15 22:10:01,870 INFO L179 ceAbstractionStarter]: Computing trace abstraction results [2023-12-15 22:10:01,889 INFO L201 PluginConnector]: Adding new model de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction CFG 15.12 10:10:01 BoogieIcfgContainer [2023-12-15 22:10:01,890 INFO L131 PluginConnector]: ------------------------ END TraceAbstraction---------------------------- [2023-12-15 22:10:01,891 INFO L158 Benchmark]: Toolchain (without parser) took 4036.36ms. Allocated memory is still 299.9MB. Free memory was 258.4MB in the beginning and 184.4MB in the end (delta: 74.0MB). Peak memory consumption was 75.6MB. Max. memory is 8.0GB. [2023-12-15 22:10:01,891 INFO L158 Benchmark]: CDTParser took 0.42ms. Allocated memory is still 194.0MB. Free memory is still 144.4MB. There was no memory consumed. Max. memory is 8.0GB. [2023-12-15 22:10:01,892 INFO L158 Benchmark]: CACSL2BoogieTranslator took 157.98ms. Allocated memory is still 299.9MB. Free memory was 258.4MB in the beginning and 246.9MB in the end (delta: 11.5MB). Peak memory consumption was 11.5MB. Max. memory is 8.0GB. [2023-12-15 22:10:01,892 INFO L158 Benchmark]: Boogie Procedure Inliner took 22.71ms. Allocated memory is still 299.9MB. Free memory was 246.9MB in the beginning and 245.3MB in the end (delta: 1.6MB). Peak memory consumption was 2.1MB. Max. memory is 8.0GB. [2023-12-15 22:10:01,892 INFO L158 Benchmark]: Boogie Preprocessor took 22.29ms. Allocated memory is still 299.9MB. Free memory was 245.3MB in the beginning and 243.7MB in the end (delta: 1.6MB). Peak memory consumption was 1.0MB. Max. memory is 8.0GB. [2023-12-15 22:10:01,892 INFO L158 Benchmark]: RCFGBuilder took 218.52ms. Allocated memory is still 299.9MB. Free memory was 243.2MB in the beginning and 229.6MB in the end (delta: 13.6MB). Peak memory consumption was 13.6MB. Max. memory is 8.0GB. [2023-12-15 22:10:01,893 INFO L158 Benchmark]: TraceAbstraction took 3609.49ms. Allocated memory is still 299.9MB. Free memory was 229.0MB in the beginning and 184.4MB in the end (delta: 44.6MB). Peak memory consumption was 46.2MB. Max. memory is 8.0GB. [2023-12-15 22:10:01,893 INFO L338 ainManager$Toolchain]: ####################### End [Toolchain 1] ####################### --- Results --- * Results from de.uni_freiburg.informatik.ultimate.core: - StatisticsResult: Toolchain Benchmarks Benchmark results are: * CDTParser took 0.42ms. Allocated memory is still 194.0MB. Free memory is still 144.4MB. There was no memory consumed. Max. memory is 8.0GB. * CACSL2BoogieTranslator took 157.98ms. Allocated memory is still 299.9MB. Free memory was 258.4MB in the beginning and 246.9MB in the end (delta: 11.5MB). Peak memory consumption was 11.5MB. Max. memory is 8.0GB. * Boogie Procedure Inliner took 22.71ms. Allocated memory is still 299.9MB. Free memory was 246.9MB in the beginning and 245.3MB in the end (delta: 1.6MB). Peak memory consumption was 2.1MB. Max. memory is 8.0GB. * Boogie Preprocessor took 22.29ms. Allocated memory is still 299.9MB. Free memory was 245.3MB in the beginning and 243.7MB in the end (delta: 1.6MB). Peak memory consumption was 1.0MB. Max. memory is 8.0GB. * RCFGBuilder took 218.52ms. Allocated memory is still 299.9MB. Free memory was 243.2MB in the beginning and 229.6MB in the end (delta: 13.6MB). Peak memory consumption was 13.6MB. Max. memory is 8.0GB. * TraceAbstraction took 3609.49ms. Allocated memory is still 299.9MB. Free memory was 229.0MB in the beginning and 184.4MB in the end (delta: 44.6MB). Peak memory consumption was 46.2MB. 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 - CounterExampleResult [Line: 17]: a call to reach_error is reachable a call to reach_error is reachable We found a FailurePath: [L22] int counter = 0; [L24] short a; [L25] long long n, x, y, z; [L26] a = __VERIFIER_nondet_ushort() [L28] n = 0 [L29] x = 0 [L30] y = 1 [L31] z = 6 VAL [a=1, counter=0, n=0, x=0, y=1, z=6] [L33] EXPR counter++ VAL [a=1, counter=1, n=0, x=0, y=1, z=6] [L33] COND TRUE counter++<1 [L34] CALL __VERIFIER_assert(z == 6 * n + 6) VAL [\old(cond)=1, counter=1] [L15] COND FALSE !(!(cond)) VAL [\old(cond)=1, cond=1, counter=1] [L34] RET __VERIFIER_assert(z == 6 * n + 6) VAL [a=1, counter=1, n=0, x=0, y=1, z=6] [L35] CALL __VERIFIER_assert(y == 3 * n * n + 3 * n + 1) VAL [\old(cond)=1, counter=1] [L15] COND FALSE !(!(cond)) VAL [\old(cond)=1, cond=1, counter=1] [L35] RET __VERIFIER_assert(y == 3 * n * n + 3 * n + 1) VAL [a=1, counter=1, n=0, x=0, y=1, z=6] [L36] CALL __VERIFIER_assert(x == n * n * n) VAL [\old(cond)=1, counter=1] [L15] COND FALSE !(!(cond)) VAL [\old(cond)=1, cond=1, counter=1] [L36] RET __VERIFIER_assert(x == n * n * n) VAL [a=1, counter=1, n=0, x=0, y=1, z=6] [L37] CALL __VERIFIER_assert(y*z - 18*x - 12*y + 2*z - 6 == 0) VAL [\old(cond)=1, counter=1] [L15] COND FALSE !(!(cond)) VAL [\old(cond)=1, cond=1, counter=1] [L37] RET __VERIFIER_assert(y*z - 18*x - 12*y + 2*z - 6 == 0) VAL [a=1, counter=1, n=0, x=0, y=1, z=6] [L38] CALL __VERIFIER_assert((z*z) - 12*y - 6*z + 12 == 0) VAL [\old(cond)=1, counter=1] [L15] COND FALSE !(!(cond)) VAL [\old(cond)=1, cond=1, counter=1] [L38] RET __VERIFIER_assert((z*z) - 12*y - 6*z + 12 == 0) VAL [a=1, counter=1, n=0, x=0, y=1, z=6] [L39] COND FALSE !(!(n <= a)) [L42] n = n + 1 [L43] x = x + y [L44] y = y + z [L45] z = z + 6 VAL [a=1, counter=1, n=1, x=1, y=7, z=12] [L33] EXPR counter++ VAL [a=1, counter=2, n=1, x=1, y=7, z=12] [L33] COND FALSE !(counter++<1) [L48] CALL __VERIFIER_assert(z == 6*n + 6) VAL [\old(cond)=1, counter=2] [L15] COND FALSE !(!(cond)) VAL [\old(cond)=1, cond=1, counter=2] [L48] RET __VERIFIER_assert(z == 6*n + 6) VAL [a=1, counter=2, n=1, x=1, y=7, z=12] [L49] CALL __VERIFIER_assert(6*a*x - x*z + 12*x == 0) VAL [\old(cond)=0, counter=2] [L15] COND TRUE !(cond) VAL [\old(cond)=0, cond=0, counter=2] [L17] reach_error() VAL [\old(cond)=0, cond=0, counter=2] - StatisticsResult: Ultimate Automizer benchmark data CFG has 2 procedures, 23 locations, 1 error locations. Started 1 CEGAR loops. OverallTime: 3.6s, OverallIterations: 7, TraceHistogramMax: 7, PathProgramHistogramMax: 1, EmptinessCheckTime: 0.0s, AutomataDifference: 1.1s, DeadEndRemovalTime: 0.0s, HoareAnnotationTime: 0.0s, InitialAbstractionConstructionTime: 0.0s, HoareTripleCheckerStatistics: 0 mSolverCounterUnknown, 138 SdHoareTripleChecker+Valid, 0.9s IncrementalHoareTripleChecker+Time, 0 mSdLazyCounter, 74 mSDsluCounter, 481 SdHoareTripleChecker+Invalid, 0.8s Time, 0 mProtectedAction, 0 SdHoareTripleChecker+Unchecked, 0 IncrementalHoareTripleChecker+Unchecked, 332 mSDsCounter, 89 IncrementalHoareTripleChecker+Valid, 0 mProtectedPredicate, 532 IncrementalHoareTripleChecker+Invalid, 621 SdHoareTripleChecker+Unknown, 0 mSolverCounterNotChecked, 89 mSolverCounterUnsat, 149 mSDtfsCounter, 532 mSolverCounterSat, 0.0s SdHoareTripleChecker+Time, 0 IncrementalHoareTripleChecker+Unknown, PredicateUnifierStatistics: 0 DeclaredPredicates, 112 GetRequests, 70 SyntacticMatches, 0 SemanticMatches, 42 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 48 ImplicationChecksByTransitivity, 0.3s Time, 0.0s BasicInterpolantAutomatonTime, BiggestAbstraction: size=64occurred in iteration=6, InterpolantAutomatonStates: 37, 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, 6 MinimizatonAttempts, 12 StatesRemovedByMinimization, 2 NontrivialMinimizations, HoareAnnotationStatistics: No data available, RefinementEngineStatistics: TRACE_CHECK: 0.0s SsaConstructionTime, 0.1s SatisfiabilityAnalysisTime, 1.1s InterpolantComputationTime, 111 NumberOfCodeBlocks, 111 NumberOfCodeBlocksAsserted, 7 NumberOfCheckSat, 113 ConstructedInterpolants, 0 QuantifiedInterpolants, 609 SizeOfPredicates, 9 NumberOfNonLiveVariables, 195 ConjunctsInSsa, 53 ConjunctsInUnsatCore, 9 InterpolantComputations, 3 PerfectInterpolantSequences, 32/56 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 RESULT: Ultimate proved your program to be incorrect! [2023-12-15 22:10:01,908 INFO L552 MonitoredProcess]: [MP /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in -t:4000 (1)] Ended with exit code 0 Received shutdown request...