/usr/bin/java -Xmx8000000000 -Xss4m -jar ./plugins/org.eclipse.equinox.launcher_1.3.100.v20150511-1540.jar -data @noDefault -ultimatedata ./data -tc ../../../trunk/examples/toolchains/AutomizerC.xml --traceabstraction.trace.refinement.strategy FIXED_PREFERENCES --traceabstraction.compute.interpolants.along.a.counterexample Craig_NestedInterpolation --traceabstraction.smt.solver Internal_SMTInterpol --traceabstraction.compute.trace.for.counterexample.result false --rcfgbuilder.size.of.a.code.block SingleStatement --traceabstraction.use.minimal.unsat.core.enumeration true --traceabstraction.additional.smt.options produce-proofs=true --traceabstraction.additional.smt.options produce-unsat-cores=true --traceabstraction.additional.smt.options enumeration-timeout=5000 --traceabstraction.additional.smt.options interpolation-heuristic=SMALLESTAMONGWIDE --traceabstraction.additional.smt.options tolerance=0.1 --traceabstraction.additional.smt.options log-additional-information=true -s ../../../trunk/examples/settings/default/automizer/svcomp-Reach-32bit-Automizer_Default.epf -i ../../../trunk/examples/svcomp/ldv-regression/alias_of_return_2.i -------------------------------------------------------------------------------- This is Ultimate 0.1.25-c90d42b [2020-09-25 10:03:59,158 INFO L177 SettingsManager]: Resetting all preferences to default values... [2020-09-25 10:03:59,162 INFO L181 SettingsManager]: Resetting UltimateCore preferences to default values [2020-09-25 10:03:59,189 INFO L184 SettingsManager]: Ultimate Commandline Interface provides no preferences, ignoring... [2020-09-25 10:03:59,190 INFO L181 SettingsManager]: Resetting Boogie Preprocessor preferences to default values [2020-09-25 10:03:59,191 INFO L181 SettingsManager]: Resetting Boogie Procedure Inliner preferences to default values [2020-09-25 10:03:59,193 INFO L181 SettingsManager]: Resetting Abstract Interpretation preferences to default values [2020-09-25 10:03:59,194 INFO L181 SettingsManager]: Resetting LassoRanker preferences to default values [2020-09-25 10:03:59,199 INFO L181 SettingsManager]: Resetting Reaching Definitions preferences to default values [2020-09-25 10:03:59,200 INFO L181 SettingsManager]: Resetting SyntaxChecker preferences to default values [2020-09-25 10:03:59,204 INFO L181 SettingsManager]: Resetting Sifa preferences to default values [2020-09-25 10:03:59,205 INFO L184 SettingsManager]: Büchi Program Product provides no preferences, ignoring... [2020-09-25 10:03:59,205 INFO L181 SettingsManager]: Resetting LTL2Aut preferences to default values [2020-09-25 10:03:59,206 INFO L181 SettingsManager]: Resetting PEA to Boogie preferences to default values [2020-09-25 10:03:59,207 INFO L181 SettingsManager]: Resetting BlockEncodingV2 preferences to default values [2020-09-25 10:03:59,209 INFO L181 SettingsManager]: Resetting ChcToBoogie preferences to default values [2020-09-25 10:03:59,212 INFO L181 SettingsManager]: Resetting AutomataScriptInterpreter preferences to default values [2020-09-25 10:03:59,214 INFO L181 SettingsManager]: Resetting BuchiAutomizer preferences to default values [2020-09-25 10:03:59,217 INFO L181 SettingsManager]: Resetting CACSL2BoogieTranslator preferences to default values [2020-09-25 10:03:59,219 INFO L181 SettingsManager]: Resetting CodeCheck preferences to default values [2020-09-25 10:03:59,221 INFO L181 SettingsManager]: Resetting InvariantSynthesis preferences to default values [2020-09-25 10:03:59,224 INFO L181 SettingsManager]: Resetting RCFGBuilder preferences to default values [2020-09-25 10:03:59,226 INFO L181 SettingsManager]: Resetting Referee preferences to default values [2020-09-25 10:03:59,227 INFO L181 SettingsManager]: Resetting TraceAbstraction preferences to default values [2020-09-25 10:03:59,236 INFO L184 SettingsManager]: TraceAbstractionConcurrent provides no preferences, ignoring... [2020-09-25 10:03:59,236 INFO L184 SettingsManager]: TraceAbstractionWithAFAs provides no preferences, ignoring... [2020-09-25 10:03:59,236 INFO L181 SettingsManager]: Resetting TreeAutomizer preferences to default values [2020-09-25 10:03:59,240 INFO L181 SettingsManager]: Resetting IcfgToChc preferences to default values [2020-09-25 10:03:59,240 INFO L181 SettingsManager]: Resetting IcfgTransformer preferences to default values [2020-09-25 10:03:59,242 INFO L184 SettingsManager]: ReqToTest provides no preferences, ignoring... [2020-09-25 10:03:59,242 INFO L181 SettingsManager]: Resetting Boogie Printer preferences to default values [2020-09-25 10:03:59,243 INFO L181 SettingsManager]: Resetting ChcSmtPrinter preferences to default values [2020-09-25 10:03:59,244 INFO L181 SettingsManager]: Resetting ReqPrinter preferences to default values [2020-09-25 10:03:59,245 INFO L181 SettingsManager]: Resetting Witness Printer preferences to default values [2020-09-25 10:03:59,255 INFO L184 SettingsManager]: Boogie PL CUP Parser provides no preferences, ignoring... [2020-09-25 10:03:59,256 INFO L181 SettingsManager]: Resetting CDTParser preferences to default values [2020-09-25 10:03:59,259 INFO L184 SettingsManager]: AutomataScriptParser provides no preferences, ignoring... [2020-09-25 10:03:59,259 INFO L184 SettingsManager]: ReqParser provides no preferences, ignoring... [2020-09-25 10:03:59,259 INFO L181 SettingsManager]: Resetting SmtParser preferences to default values [2020-09-25 10:03:59,260 INFO L181 SettingsManager]: Resetting Witness Parser preferences to default values [2020-09-25 10:03:59,263 INFO L188 SettingsManager]: Finished resetting all preferences to default values... [2020-09-25 10:03:59,264 INFO L101 SettingsManager]: Beginning loading settings from /storage/repos/ultimate-2/releaseScripts/default/UAutomizer-linux/../../../trunk/examples/settings/default/automizer/svcomp-Reach-32bit-Automizer_Default.epf [2020-09-25 10:03:59,319 INFO L113 SettingsManager]: Loading preferences was successful [2020-09-25 10:03:59,319 INFO L115 SettingsManager]: Preferences different from defaults after loading the file: [2020-09-25 10:03:59,323 INFO L136 SettingsManager]: Preferences of BlockEncodingV2 differ from their defaults: [2020-09-25 10:03:59,323 INFO L138 SettingsManager]: * Create parallel compositions if possible=false [2020-09-25 10:03:59,323 INFO L138 SettingsManager]: * Use SBE=true [2020-09-25 10:03:59,324 INFO L136 SettingsManager]: Preferences of CACSL2BoogieTranslator differ from their defaults: [2020-09-25 10:03:59,324 INFO L138 SettingsManager]: * sizeof long=4 [2020-09-25 10:03:59,324 INFO L138 SettingsManager]: * Overapproximate operations on floating types=true [2020-09-25 10:03:59,324 INFO L138 SettingsManager]: * sizeof POINTER=4 [2020-09-25 10:03:59,324 INFO L138 SettingsManager]: * Check division by zero=IGNORE [2020-09-25 10:03:59,325 INFO L138 SettingsManager]: * Pointer to allocated memory at dereference=IGNORE [2020-09-25 10:03:59,325 INFO L138 SettingsManager]: * If two pointers are subtracted or compared they have the same base address=IGNORE [2020-09-25 10:03:59,325 INFO L138 SettingsManager]: * Check array bounds for arrays that are off heap=IGNORE [2020-09-25 10:03:59,325 INFO L138 SettingsManager]: * sizeof long double=12 [2020-09-25 10:03:59,325 INFO L138 SettingsManager]: * Check if freed pointer was valid=false [2020-09-25 10:03:59,325 INFO L138 SettingsManager]: * Use constant arrays=true [2020-09-25 10:03:59,326 INFO L138 SettingsManager]: * Pointer base address is valid at dereference=IGNORE [2020-09-25 10:03:59,326 INFO L136 SettingsManager]: Preferences of RCFGBuilder differ from their defaults: [2020-09-25 10:03:59,326 INFO L138 SettingsManager]: * Size of a code block=SequenceOfStatements [2020-09-25 10:03:59,326 INFO L138 SettingsManager]: * To the following directory=./dump/ [2020-09-25 10:03:59,327 INFO L138 SettingsManager]: * SMT solver=External_DefaultMode [2020-09-25 10:03:59,327 INFO L138 SettingsManager]: * Command for external solver=z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in -t:2000 [2020-09-25 10:03:59,327 INFO L136 SettingsManager]: Preferences of TraceAbstraction differ from their defaults: [2020-09-25 10:03:59,327 INFO L138 SettingsManager]: * Compute Interpolants along a Counterexample=FPandBP [2020-09-25 10:03:59,328 INFO L138 SettingsManager]: * Positions where we compute the Hoare Annotation=LoopsAndPotentialCycles [2020-09-25 10:03:59,328 INFO L138 SettingsManager]: * Trace refinement strategy=CAMEL [2020-09-25 10:03:59,328 INFO L138 SettingsManager]: * Command for external solver=z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in [2020-09-25 10:03:59,328 INFO L138 SettingsManager]: * Compute Hoare Annotation of negated interpolant automaton, abstraction and CFG=true [2020-09-25 10:03:59,328 INFO L138 SettingsManager]: * Trace refinement exception blacklist=NONE [2020-09-25 10:03:59,329 INFO L138 SettingsManager]: * SMT solver=External_ModelsAndUnsatCoreMode Applying setting for plugin de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction: Trace refinement strategy -> FIXED_PREFERENCES Applying setting for plugin de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction: Compute Interpolants along a Counterexample -> Craig_NestedInterpolation Applying setting for plugin de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction: SMT solver -> Internal_SMTInterpol Applying setting for plugin de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction: Compute trace for counterexample result -> false Applying setting for plugin de.uni_freiburg.informatik.ultimate.plugins.generator.rcfgbuilder: Size of a code block -> SingleStatement Applying setting for plugin de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction: Use minimal unsat core enumeration -> true Applying setting for plugin de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction: Additional SMT options -> produce-proofs=true;produce-unsat-cores=true;enumeration-timeout=5000;interpolation-heuristic=SMALLESTAMONGWIDE;tolerance=0.1;log-additional-information=true; Applying setting for plugin de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction: Additional SMT options -> produce-proofs=true;produce-unsat-cores=true;enumeration-timeout=5000;interpolation-heuristic=SMALLESTAMONGWIDE;tolerance=0.1;log-additional-information=true; Applying setting for plugin de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction: Additional SMT options -> produce-proofs=true;produce-unsat-cores=true;enumeration-timeout=5000;interpolation-heuristic=SMALLESTAMONGWIDE;tolerance=0.1;log-additional-information=true; Applying setting for plugin de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction: Additional SMT options -> produce-proofs=true;produce-unsat-cores=true;enumeration-timeout=5000;interpolation-heuristic=SMALLESTAMONGWIDE;tolerance=0.1;log-additional-information=true; Applying setting for plugin de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction: Additional SMT options -> produce-proofs=true;produce-unsat-cores=true;enumeration-timeout=5000;interpolation-heuristic=SMALLESTAMONGWIDE;tolerance=0.1;log-additional-information=true; Applying setting for plugin de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction: Additional SMT options -> produce-proofs=true;produce-unsat-cores=true;enumeration-timeout=5000;interpolation-heuristic=SMALLESTAMONGWIDE;tolerance=0.1;log-additional-information=true; [2020-09-25 10:03:59,774 INFO L75 nceAwareModelManager]: Repository-Root is: /tmp [2020-09-25 10:03:59,793 INFO L258 ainManager$Toolchain]: [Toolchain 1]: Applicable parser(s) successfully (re)initialized [2020-09-25 10:03:59,797 INFO L214 ainManager$Toolchain]: [Toolchain 1]: Toolchain selected. [2020-09-25 10:03:59,799 INFO L271 PluginConnector]: Initializing CDTParser... [2020-09-25 10:03:59,800 INFO L275 PluginConnector]: CDTParser initialized [2020-09-25 10:03:59,801 INFO L429 ainManager$Toolchain]: [Toolchain 1]: Parsing single file: /storage/repos/ultimate-2/releaseScripts/default/UAutomizer-linux/../../../trunk/examples/svcomp/ldv-regression/alias_of_return_2.i [2020-09-25 10:03:59,894 INFO L220 CDTParser]: Created temporary CDT project at /storage/repos/ultimate-2/releaseScripts/default/UAutomizer-linux/data/4c4c823d9/b386f239c7d14367beb9ff333a776fd8/FLAG5015524b7 [2020-09-25 10:04:00,423 INFO L306 CDTParser]: Found 1 translation units. [2020-09-25 10:04:00,424 INFO L160 CDTParser]: Scanning /storage/repos/ultimate-2/trunk/examples/svcomp/ldv-regression/alias_of_return_2.i [2020-09-25 10:04:00,432 INFO L349 CDTParser]: About to delete temporary CDT project at /storage/repos/ultimate-2/releaseScripts/default/UAutomizer-linux/data/4c4c823d9/b386f239c7d14367beb9ff333a776fd8/FLAG5015524b7 [2020-09-25 10:04:00,769 INFO L357 CDTParser]: Successfully deleted /storage/repos/ultimate-2/releaseScripts/default/UAutomizer-linux/data/4c4c823d9/b386f239c7d14367beb9ff333a776fd8 [2020-09-25 10:04:00,782 INFO L296 ainManager$Toolchain]: ####################### [Toolchain 1] ####################### [2020-09-25 10:04:00,788 INFO L131 ToolchainWalker]: Walking toolchain with 4 elements. [2020-09-25 10:04:00,789 INFO L113 PluginConnector]: ------------------------CACSL2BoogieTranslator---------------------------- [2020-09-25 10:04:00,790 INFO L271 PluginConnector]: Initializing CACSL2BoogieTranslator... [2020-09-25 10:04:00,794 INFO L275 PluginConnector]: CACSL2BoogieTranslator initialized [2020-09-25 10:04:00,795 INFO L185 PluginConnector]: Executing the observer ACSLObjectContainerObserver from plugin CACSL2BoogieTranslator for "CDTParser AST 25.09 10:04:00" (1/1) ... [2020-09-25 10:04:00,799 INFO L205 PluginConnector]: Invalid model from CACSL2BoogieTranslator for observer de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator.ACSLObjectContainerObserver@1987833a and model type de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 25.09 10:04:00, skipping insertion in model container [2020-09-25 10:04:00,799 INFO L185 PluginConnector]: Executing the observer CACSL2BoogieTranslatorObserver from plugin CACSL2BoogieTranslator for "CDTParser AST 25.09 10:04:00" (1/1) ... [2020-09-25 10:04:00,809 INFO L145 MainTranslator]: Starting translation in SV-COMP mode [2020-09-25 10:04:00,834 INFO L178 MainTranslator]: Built tables and reachable declarations [2020-09-25 10:04:01,095 INFO L206 PostProcessor]: Analyzing one entry point: main [2020-09-25 10:04:01,110 INFO L203 MainTranslator]: Completed pre-run [2020-09-25 10:04:01,127 INFO L206 PostProcessor]: Analyzing one entry point: main [2020-09-25 10:04:01,144 INFO L208 MainTranslator]: Completed translation [2020-09-25 10:04:01,145 INFO L202 PluginConnector]: Adding new model de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 25.09 10:04:01 WrapperNode [2020-09-25 10:04:01,145 INFO L132 PluginConnector]: ------------------------ END CACSL2BoogieTranslator---------------------------- [2020-09-25 10:04:01,146 INFO L113 PluginConnector]: ------------------------Boogie Preprocessor---------------------------- [2020-09-25 10:04:01,146 INFO L271 PluginConnector]: Initializing Boogie Preprocessor... [2020-09-25 10:04:01,146 INFO L275 PluginConnector]: Boogie Preprocessor initialized [2020-09-25 10:04:01,160 INFO L185 PluginConnector]: Executing the observer EnsureBoogieModelObserver from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 25.09 10:04:01" (1/1) ... [2020-09-25 10:04:01,161 INFO L185 PluginConnector]: Executing the observer TypeChecker from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 25.09 10:04:01" (1/1) ... [2020-09-25 10:04:01,259 INFO L185 PluginConnector]: Executing the observer ConstExpander from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 25.09 10:04:01" (1/1) ... [2020-09-25 10:04:01,259 INFO L185 PluginConnector]: Executing the observer StructExpander from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 25.09 10:04:01" (1/1) ... [2020-09-25 10:04:01,265 INFO L185 PluginConnector]: Executing the observer UnstructureCode from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 25.09 10:04:01" (1/1) ... [2020-09-25 10:04:01,267 INFO L185 PluginConnector]: Executing the observer FunctionInliner from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 25.09 10:04:01" (1/1) ... [2020-09-25 10:04:01,268 INFO L185 PluginConnector]: Executing the observer BoogieSymbolTableConstructor from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 25.09 10:04:01" (1/1) ... [2020-09-25 10:04:01,271 INFO L132 PluginConnector]: ------------------------ END Boogie Preprocessor---------------------------- [2020-09-25 10:04:01,271 INFO L113 PluginConnector]: ------------------------RCFGBuilder---------------------------- [2020-09-25 10:04:01,272 INFO L271 PluginConnector]: Initializing RCFGBuilder... [2020-09-25 10:04:01,272 INFO L275 PluginConnector]: RCFGBuilder initialized [2020-09-25 10:04:01,273 INFO L185 PluginConnector]: Executing the observer RCFGBuilderObserver from plugin RCFGBuilder for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 25.09 10:04:01" (1/1) ... No working directory specified, using /storage/repos/ultimate-2/releaseScripts/default/UAutomizer-linux/z3 Starting monitored process 1 with z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in -t:2000 (exit command is (exit), workingDir is null) Waiting until toolchain timeout for monitored process 1 with z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in -t:2000 [2020-09-25 10:04:01,347 INFO L138 BoogieDeclarations]: Found implementation of procedure ULTIMATE.init [2020-09-25 10:04:01,347 INFO L138 BoogieDeclarations]: Found implementation of procedure ULTIMATE.start [2020-09-25 10:04:01,347 INFO L138 BoogieDeclarations]: Found implementation of procedure err [2020-09-25 10:04:01,347 INFO L138 BoogieDeclarations]: Found implementation of procedure return_self [2020-09-25 10:04:01,347 INFO L138 BoogieDeclarations]: Found implementation of procedure main [2020-09-25 10:04:01,348 INFO L130 BoogieDeclarations]: Found specification of procedure __VERIFIER_error [2020-09-25 10:04:01,348 INFO L130 BoogieDeclarations]: Found specification of procedure err [2020-09-25 10:04:01,348 INFO L130 BoogieDeclarations]: Found specification of procedure __VERIFIER_nondet_int [2020-09-25 10:04:01,348 INFO L130 BoogieDeclarations]: Found specification of procedure return_self [2020-09-25 10:04:01,348 INFO L130 BoogieDeclarations]: Found specification of procedure main [2020-09-25 10:04:01,349 INFO L130 BoogieDeclarations]: Found specification of procedure #Ultimate.allocOnStack [2020-09-25 10:04:01,349 INFO L130 BoogieDeclarations]: Found specification of procedure write~int [2020-09-25 10:04:01,349 INFO L130 BoogieDeclarations]: Found specification of procedure read~int [2020-09-25 10:04:01,349 INFO L130 BoogieDeclarations]: Found specification of procedure ULTIMATE.dealloc [2020-09-25 10:04:01,349 INFO L130 BoogieDeclarations]: Found specification of procedure ULTIMATE.init [2020-09-25 10:04:01,350 INFO L130 BoogieDeclarations]: Found specification of procedure ULTIMATE.start [2020-09-25 10:04:01,608 INFO L290 CfgBuilder]: Using the 1 location(s) as analysis (start of procedure ULTIMATE.start) [2020-09-25 10:04:01,608 INFO L295 CfgBuilder]: Removed 0 assume(true) statements. [2020-09-25 10:04:01,624 INFO L202 PluginConnector]: Adding new model de.uni_freiburg.informatik.ultimate.plugins.generator.rcfgbuilder CFG 25.09 10:04:01 BoogieIcfgContainer [2020-09-25 10:04:01,625 INFO L132 PluginConnector]: ------------------------ END RCFGBuilder---------------------------- [2020-09-25 10:04:01,638 INFO L113 PluginConnector]: ------------------------TraceAbstraction---------------------------- [2020-09-25 10:04:01,638 INFO L271 PluginConnector]: Initializing TraceAbstraction... [2020-09-25 10:04:01,645 INFO L275 PluginConnector]: TraceAbstraction initialized [2020-09-25 10:04:01,645 INFO L185 PluginConnector]: Executing the observer TraceAbstractionObserver from plugin TraceAbstraction for "CDTParser AST 25.09 10:04:00" (1/3) ... [2020-09-25 10:04:01,646 INFO L205 PluginConnector]: Invalid model from TraceAbstraction for observer de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction.TraceAbstractionObserver@648c711c and model type de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction AST 25.09 10:04:01, skipping insertion in model container [2020-09-25 10:04:01,647 INFO L185 PluginConnector]: Executing the observer TraceAbstractionObserver from plugin TraceAbstraction for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 25.09 10:04:01" (2/3) ... [2020-09-25 10:04:01,648 INFO L205 PluginConnector]: Invalid model from TraceAbstraction for observer de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction.TraceAbstractionObserver@648c711c and model type de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction AST 25.09 10:04:01, skipping insertion in model container [2020-09-25 10:04:01,649 INFO L185 PluginConnector]: Executing the observer TraceAbstractionObserver from plugin TraceAbstraction for "de.uni_freiburg.informatik.ultimate.plugins.generator.rcfgbuilder CFG 25.09 10:04:01" (3/3) ... [2020-09-25 10:04:01,651 INFO L109 eAbstractionObserver]: Analyzing ICFG alias_of_return_2.i [2020-09-25 10:04:01,668 INFO L157 ceAbstractionStarter]: Automizer settings: Hoare:true NWA Interpolation:Craig_NestedInterpolation Determinization: PREDICATE_ABSTRACTION [2020-09-25 10:04:01,679 INFO L169 ceAbstractionStarter]: Appying trace abstraction to program that has 1 error locations. [2020-09-25 10:04:01,700 INFO L251 AbstractCegarLoop]: Starting to check reachability of 1 error locations. [2020-09-25 10:04:01,732 INFO L375 AbstractCegarLoop]: Interprodecural is true [2020-09-25 10:04:01,733 INFO L376 AbstractCegarLoop]: Hoare is true [2020-09-25 10:04:01,733 INFO L377 AbstractCegarLoop]: Compute interpolants for Craig_NestedInterpolation [2020-09-25 10:04:01,733 INFO L378 AbstractCegarLoop]: Backedges is STRAIGHT_LINE [2020-09-25 10:04:01,733 INFO L379 AbstractCegarLoop]: Determinization is PREDICATE_ABSTRACTION [2020-09-25 10:04:01,733 INFO L380 AbstractCegarLoop]: Difference is false [2020-09-25 10:04:01,733 INFO L381 AbstractCegarLoop]: Minimize is MINIMIZE_SEVPA [2020-09-25 10:04:01,734 INFO L385 AbstractCegarLoop]: ======== Iteration 0==of CEGAR loop == AllErrorsAtOnce======== [2020-09-25 10:04:01,758 INFO L276 IsEmpty]: Start isEmpty. Operand 38 states. [2020-09-25 10:04:01,765 INFO L282 IsEmpty]: Finished isEmpty. Found accepting run of length 27 [2020-09-25 10:04:01,765 INFO L414 BasicCegarLoop]: Found error trace [2020-09-25 10:04:01,766 INFO L422 BasicCegarLoop]: trace histogram [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] [2020-09-25 10:04:01,767 INFO L427 AbstractCegarLoop]: === Iteration 1 === [errErr0ASSERT_VIOLATIONERROR_FUNCTION]=== [2020-09-25 10:04:01,773 INFO L144 PredicateUnifier]: Initialized classic predicate unifier [2020-09-25 10:04:01,773 INFO L82 PathProgramCache]: Analyzing trace with hash -390061783, now seen corresponding path program 1 times [2020-09-25 10:04:01,782 INFO L163 FreeRefinementEngine]: Executing refinement strategy FIXED_PREFERENCES [2020-09-25 10:04:01,783 INFO L354 FreeRefinementEngine]: Using trace check IpTcStrategyModulePreferences [315543389] [2020-09-25 10:04:01,783 INFO L95 rtionOrderModulation]: Keeping assertion order NOT_INCREMENTALLY [2020-09-25 10:04:01,928 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2020-09-25 10:04:01,967 FATAL L256 erpolLogProxyWrapper]: Now shrinking... [2020-09-25 10:04:02,370 FATAL L256 erpolLogProxyWrapper]: Timeout: 5000 [2020-09-25 10:04:02,370 FATAL L256 erpolLogProxyWrapper]: Cardinality of Constraint set: 37 [2020-09-25 10:04:02,371 FATAL L256 erpolLogProxyWrapper]: Number of enumerated Muses: 1 [2020-09-25 10:04:02,371 FATAL L256 erpolLogProxyWrapper]: Time needed for enumeration: 436 [2020-09-25 10:04:02,374 FATAL L256 erpolLogProxyWrapper]: Heuristic: SMALLESTAMONGWIDE [2020-09-25 10:04:02,375 FATAL L256 erpolLogProxyWrapper]: Tolerance: 0.1 [2020-09-25 10:04:02,375 FATAL L256 erpolLogProxyWrapper]: Chosen Mus has size: 8 [2020-09-25 10:04:02,375 FATAL L256 erpolLogProxyWrapper]: Chosen Mus has depth: 18 [2020-09-25 10:04:02,376 FATAL L256 erpolLogProxyWrapper]: Chosen Mus has width: 14 [2020-09-25 10:04:02,376 FATAL L256 erpolLogProxyWrapper]: Time needed for Heuristics: 4 [2020-09-25 10:04:02,501 INFO L375 atingTraceCheckCraig]: Compute interpolants for subsequence at non-pending call position 0 [2020-09-25 10:04:02,504 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2020-09-25 10:04:02,507 FATAL L256 erpolLogProxyWrapper]: Now shrinking... [2020-09-25 10:04:02,516 FATAL L256 erpolLogProxyWrapper]: Timeout: 5000 [2020-09-25 10:04:02,516 FATAL L256 erpolLogProxyWrapper]: Cardinality of Constraint set: 11 [2020-09-25 10:04:02,517 FATAL L256 erpolLogProxyWrapper]: Number of enumerated Muses: 1 [2020-09-25 10:04:02,517 FATAL L256 erpolLogProxyWrapper]: Time needed for enumeration: 10 [2020-09-25 10:04:02,517 FATAL L256 erpolLogProxyWrapper]: Heuristic: SMALLESTAMONGWIDE [2020-09-25 10:04:02,517 FATAL L256 erpolLogProxyWrapper]: Tolerance: 0.1 [2020-09-25 10:04:02,518 FATAL L256 erpolLogProxyWrapper]: Chosen Mus has size: 1 [2020-09-25 10:04:02,518 FATAL L256 erpolLogProxyWrapper]: Chosen Mus has depth: 2 [2020-09-25 10:04:02,518 FATAL L256 erpolLogProxyWrapper]: Chosen Mus has width: 1 [2020-09-25 10:04:02,519 FATAL L256 erpolLogProxyWrapper]: Time needed for Heuristics: 1 [2020-09-25 10:04:02,525 INFO L375 atingTraceCheckCraig]: Compute interpolants for subsequence at non-pending call position 10 [2020-09-25 10:04:02,533 INFO L136 AnnotateAndAsserter]: Conjunction of SSA is unsat [2020-09-25 10:04:02,538 FATAL L256 erpolLogProxyWrapper]: Now shrinking... [2020-09-25 10:04:02,581 FATAL L256 erpolLogProxyWrapper]: Timeout: 5000 [2020-09-25 10:04:02,582 FATAL L256 erpolLogProxyWrapper]: Cardinality of Constraint set: 13 [2020-09-25 10:04:02,582 FATAL L256 erpolLogProxyWrapper]: Number of enumerated Muses: 1 [2020-09-25 10:04:02,582 FATAL L256 erpolLogProxyWrapper]: Time needed for enumeration: 47 [2020-09-25 10:04:02,583 FATAL L256 erpolLogProxyWrapper]: Heuristic: SMALLESTAMONGWIDE [2020-09-25 10:04:02,583 FATAL L256 erpolLogProxyWrapper]: Tolerance: 0.1 [2020-09-25 10:04:02,583 FATAL L256 erpolLogProxyWrapper]: Chosen Mus has size: 5 [2020-09-25 10:04:02,584 FATAL L256 erpolLogProxyWrapper]: Chosen Mus has depth: 2 [2020-09-25 10:04:02,584 FATAL L256 erpolLogProxyWrapper]: Chosen Mus has width: 10 [2020-09-25 10:04:02,584 FATAL L256 erpolLogProxyWrapper]: Time needed for Heuristics: 1 [2020-09-25 10:04:02,635 INFO L134 CoverageAnalysis]: Checked inductivity of 0 backedges. 0 proven. 0 refuted. 0 times theorem prover too weak. 0 trivial. 0 not checked. [2020-09-25 10:04:02,636 INFO L354 FreeRefinementEngine]: Using interpolant generator IpTcStrategyModulePreferences [315543389] [2020-09-25 10:04:02,638 INFO L220 FreeRefinementEngine]: Constructing automaton from 1 perfect and 0 imperfect interpolant sequences. [2020-09-25 10:04:02,638 INFO L233 FreeRefinementEngine]: Number of different interpolants: perfect sequences [9] imperfect sequences [] total 9 [2020-09-25 10:04:02,640 INFO L156 tionRefinementEngine]: Using interpolant automaton builder IpAbStrategyModuleStraightlineAll [1551718714] [2020-09-25 10:04:02,646 INFO L459 AbstractCegarLoop]: Interpolant automaton has 9 states [2020-09-25 10:04:02,646 INFO L143 FreeRefinementEngine]: Using predicate unifier PredicateUnifier provided by strategy FIXED_PREFERENCES [2020-09-25 10:04:02,664 INFO L142 InterpolantAutomaton]: Constructing interpolant automaton starting with 9 interpolants. [2020-09-25 10:04:02,665 INFO L144 InterpolantAutomaton]: CoverageRelationStatistics Valid=15, Invalid=57, Unknown=0, NotChecked=0, Total=72 [2020-09-25 10:04:02,667 INFO L87 Difference]: Start difference. First operand 38 states. Second operand 9 states. [2020-09-25 10:04:02,959 INFO L144 Difference]: Subtrahend was deterministic. Have not used determinization. [2020-09-25 10:04:02,959 INFO L93 Difference]: Finished difference Result 44 states and 44 transitions. [2020-09-25 10:04:02,960 INFO L141 InterpolantAutomaton]: Switched to read-only mode: deterministic interpolant automaton has 10 states. [2020-09-25 10:04:02,962 INFO L78 Accepts]: Start accepts. Automaton has 9 states. Word has length 26 [2020-09-25 10:04:02,962 INFO L84 Accepts]: Finished accepts. some prefix is accepted. [2020-09-25 10:04:02,971 INFO L225 Difference]: With dead ends: 44 [2020-09-25 10:04:02,972 INFO L226 Difference]: Without dead ends: 0 [2020-09-25 10:04:02,977 INFO L675 BasicCegarLoop]: 0 DeclaredPredicates, 16 GetRequests, 4 SyntacticMatches, 0 SemanticMatches, 12 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 8 ImplicationChecksByTransitivity, 0.2s TimeCoverageRelationStatistics Valid=39, Invalid=143, Unknown=0, NotChecked=0, Total=182 [2020-09-25 10:04:03,010 INFO L82 GeneralOperation]: Start minimizeSevpa. Operand 0 states. [2020-09-25 10:04:03,018 INFO L88 GeneralOperation]: Finished minimizeSevpa. Reduced states from 0 to 0. [2020-09-25 10:04:03,019 INFO L82 GeneralOperation]: Start removeUnreachable. Operand 0 states. [2020-09-25 10:04:03,020 INFO L88 GeneralOperation]: Finished removeUnreachable. Reduced from 0 states to 0 states and 0 transitions. [2020-09-25 10:04:03,021 INFO L78 Accepts]: Start accepts. Automaton has 0 states and 0 transitions. Word has length 26 [2020-09-25 10:04:03,021 INFO L84 Accepts]: Finished accepts. word is rejected. [2020-09-25 10:04:03,021 INFO L479 AbstractCegarLoop]: Abstraction has 0 states and 0 transitions. [2020-09-25 10:04:03,022 INFO L480 AbstractCegarLoop]: Interpolant automaton has 9 states. [2020-09-25 10:04:03,022 INFO L276 IsEmpty]: Start isEmpty. Operand 0 states and 0 transitions. [2020-09-25 10:04:03,022 INFO L282 IsEmpty]: Finished isEmpty. No accepting run. [2020-09-25 10:04:03,022 WARN L516 AbstractCegarLoop]: Destroyed unattended storables created during the last iteration: SelfDestructingSolverStorable0 [2020-09-25 10:04:03,024 INFO L343 DoubleDeckerVisitor]: Before removal of dead ends 0 states and 0 transitions. [2020-09-25 10:04:03,092 INFO L268 CegarLoopResult]: For program point L17(line 17) no Hoare annotation was computed. [2020-09-25 10:04:03,093 INFO L271 CegarLoopResult]: At program point return_selfENTRY(lines 12 19) the Hoare annotation is: true [2020-09-25 10:04:03,093 INFO L268 CegarLoopResult]: For program point L15(line 15) no Hoare annotation was computed. [2020-09-25 10:04:03,093 INFO L268 CegarLoopResult]: For program point L14(line 14) no Hoare annotation was computed. [2020-09-25 10:04:03,093 INFO L268 CegarLoopResult]: For program point L14-1(lines 14 18) no Hoare annotation was computed. [2020-09-25 10:04:03,093 INFO L268 CegarLoopResult]: For program point L14-2(line 14) no Hoare annotation was computed. [2020-09-25 10:04:03,093 INFO L268 CegarLoopResult]: For program point L14-3(line 14) no Hoare annotation was computed. [2020-09-25 10:04:03,094 INFO L268 CegarLoopResult]: For program point return_selfFINAL(lines 12 19) no Hoare annotation was computed. [2020-09-25 10:04:03,094 INFO L268 CegarLoopResult]: For program point return_selfEXIT(lines 12 19) no Hoare annotation was computed. [2020-09-25 10:04:03,094 INFO L268 CegarLoopResult]: For program point L-1(line -1) no Hoare annotation was computed. [2020-09-25 10:04:03,094 INFO L268 CegarLoopResult]: For program point L-1-1(line -1) no Hoare annotation was computed. [2020-09-25 10:04:03,094 INFO L268 CegarLoopResult]: For program point ULTIMATE.initFINAL(line -1) no Hoare annotation was computed. [2020-09-25 10:04:03,095 INFO L264 CegarLoopResult]: At program point ULTIMATE.initENTRY(line -1) the Hoare annotation is: (and (= |#NULL.base| |old(#NULL.base)|) (= |#NULL.offset| |old(#NULL.offset)|) (= |old(#valid)| |#valid|)) [2020-09-25 10:04:03,095 INFO L268 CegarLoopResult]: For program point ULTIMATE.initEXIT(line -1) no Hoare annotation was computed. [2020-09-25 10:04:03,095 INFO L268 CegarLoopResult]: For program point errErr0ASSERT_VIOLATIONERROR_FUNCTION(line 8) no Hoare annotation was computed. [2020-09-25 10:04:03,095 INFO L268 CegarLoopResult]: For program point errEXIT(lines 7 8) no Hoare annotation was computed. [2020-09-25 10:04:03,095 INFO L271 CegarLoopResult]: At program point errENTRY(lines 7 8) the Hoare annotation is: true [2020-09-25 10:04:03,096 INFO L268 CegarLoopResult]: For program point errFINAL(lines 7 8) no Hoare annotation was computed. [2020-09-25 10:04:03,096 INFO L268 CegarLoopResult]: For program point ULTIMATE.startEXIT(line -1) no Hoare annotation was computed. [2020-09-25 10:04:03,096 INFO L271 CegarLoopResult]: At program point L-1(line -1) the Hoare annotation is: true [2020-09-25 10:04:03,096 INFO L271 CegarLoopResult]: At program point ULTIMATE.startENTRY(line -1) the Hoare annotation is: true [2020-09-25 10:04:03,096 INFO L268 CegarLoopResult]: For program point ULTIMATE.startFINAL(line -1) no Hoare annotation was computed. [2020-09-25 10:04:03,096 INFO L268 CegarLoopResult]: For program point L34-1(line 34) no Hoare annotation was computed. [2020-09-25 10:04:03,097 INFO L268 CegarLoopResult]: For program point L32(line 32) no Hoare annotation was computed. [2020-09-25 10:04:03,097 INFO L264 CegarLoopResult]: At program point L34-2(line 34) the Hoare annotation is: false [2020-09-25 10:04:03,097 INFO L268 CegarLoopResult]: For program point L32-1(line 32) no Hoare annotation was computed. [2020-09-25 10:04:03,097 INFO L268 CegarLoopResult]: For program point L34-4(line 34) no Hoare annotation was computed. [2020-09-25 10:04:03,097 INFO L264 CegarLoopResult]: At program point mainENTRY(lines 21 35) the Hoare annotation is: (= |old(#valid)| |#valid|) [2020-09-25 10:04:03,098 INFO L268 CegarLoopResult]: For program point L29(line 29) no Hoare annotation was computed. [2020-09-25 10:04:03,098 INFO L268 CegarLoopResult]: For program point L34-5(line 34) no Hoare annotation was computed. [2020-09-25 10:04:03,098 INFO L268 CegarLoopResult]: For program point L29-1(line 29) no Hoare annotation was computed. [2020-09-25 10:04:03,098 INFO L268 CegarLoopResult]: For program point L25(line 25) no Hoare annotation was computed. [2020-09-25 10:04:03,098 INFO L268 CegarLoopResult]: For program point mainEXIT(lines 21 35) no Hoare annotation was computed. [2020-09-25 10:04:03,098 INFO L271 CegarLoopResult]: At program point L25-1(line 25) the Hoare annotation is: true [2020-09-25 10:04:03,099 INFO L268 CegarLoopResult]: For program point L23(line 23) no Hoare annotation was computed. [2020-09-25 10:04:03,099 INFO L268 CegarLoopResult]: For program point L23-1(line 23) no Hoare annotation was computed. [2020-09-25 10:04:03,099 INFO L268 CegarLoopResult]: For program point mainFINAL(lines 21 35) no Hoare annotation was computed. [2020-09-25 10:04:03,099 INFO L268 CegarLoopResult]: For program point L34(line 34) no Hoare annotation was computed. [2020-09-25 10:04:03,107 INFO L202 PluginConnector]: Adding new model de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction CFG 25.09 10:04:03 BoogieIcfgContainer [2020-09-25 10:04:03,108 INFO L132 PluginConnector]: ------------------------ END TraceAbstraction---------------------------- [2020-09-25 10:04:03,111 INFO L168 Benchmark]: Toolchain (without parser) took 2326.14 ms. Allocated memory was 144.2 MB in the beginning and 236.5 MB in the end (delta: 92.3 MB). Free memory was 103.1 MB in the beginning and 199.7 MB in the end (delta: -96.6 MB). There was no memory consumed. Max. memory is 7.1 GB. [2020-09-25 10:04:03,112 INFO L168 Benchmark]: CDTParser took 0.23 ms. Allocated memory is still 144.2 MB. Free memory was 120.9 MB in the beginning and 120.7 MB in the end (delta: 210.0 kB). Peak memory consumption was 210.0 kB. Max. memory is 7.1 GB. [2020-09-25 10:04:03,113 INFO L168 Benchmark]: CACSL2BoogieTranslator took 356.19 ms. Allocated memory is still 144.2 MB. Free memory was 102.4 MB in the beginning and 93.0 MB in the end (delta: 9.5 MB). Peak memory consumption was 9.5 MB. Max. memory is 7.1 GB. [2020-09-25 10:04:03,114 INFO L168 Benchmark]: Boogie Preprocessor took 125.05 ms. Allocated memory was 144.2 MB in the beginning and 203.4 MB in the end (delta: 59.2 MB). Free memory was 93.0 MB in the beginning and 181.9 MB in the end (delta: -88.9 MB). Peak memory consumption was 10.1 MB. Max. memory is 7.1 GB. [2020-09-25 10:04:03,115 INFO L168 Benchmark]: RCFGBuilder took 354.00 ms. Allocated memory is still 203.4 MB. Free memory was 181.9 MB in the beginning and 167.3 MB in the end (delta: 14.6 MB). Peak memory consumption was 14.6 MB. Max. memory is 7.1 GB. [2020-09-25 10:04:03,117 INFO L168 Benchmark]: TraceAbstraction took 1470.14 ms. Allocated memory was 203.4 MB in the beginning and 236.5 MB in the end (delta: 33.0 MB). Free memory was 166.6 MB in the beginning and 199.7 MB in the end (delta: -33.0 MB). There was no memory consumed. Max. memory is 7.1 GB. [2020-09-25 10:04:03,122 INFO L336 ainManager$Toolchain]: ####################### End [Toolchain 1] ####################### --- Results --- * Results from de.uni_freiburg.informatik.ultimate.core: - StatisticsResult: Toolchain Benchmarks Benchmark results are: * CDTParser took 0.23 ms. Allocated memory is still 144.2 MB. Free memory was 120.9 MB in the beginning and 120.7 MB in the end (delta: 210.0 kB). Peak memory consumption was 210.0 kB. Max. memory is 7.1 GB. * CACSL2BoogieTranslator took 356.19 ms. Allocated memory is still 144.2 MB. Free memory was 102.4 MB in the beginning and 93.0 MB in the end (delta: 9.5 MB). Peak memory consumption was 9.5 MB. Max. memory is 7.1 GB. * Boogie Preprocessor took 125.05 ms. Allocated memory was 144.2 MB in the beginning and 203.4 MB in the end (delta: 59.2 MB). Free memory was 93.0 MB in the beginning and 181.9 MB in the end (delta: -88.9 MB). Peak memory consumption was 10.1 MB. Max. memory is 7.1 GB. * RCFGBuilder took 354.00 ms. Allocated memory is still 203.4 MB. Free memory was 181.9 MB in the beginning and 167.3 MB in the end (delta: 14.6 MB). Peak memory consumption was 14.6 MB. Max. memory is 7.1 GB. * TraceAbstraction took 1470.14 ms. Allocated memory was 203.4 MB in the beginning and 236.5 MB in the end (delta: 33.0 MB). Free memory was 166.6 MB in the beginning and 199.7 MB in the end (delta: -33.0 MB). There was no memory consumed. Max. memory is 7.1 GB. * Results from de.uni_freiburg.informatik.ultimate.plugins.generator.traceabstraction: - PositiveResult [Line: 8]: call of __VERIFIER_error() unreachable For all program executions holds that call of __VERIFIER_error() unreachable at this location - AllSpecificationsHoldResult: All specifications hold 1 specifications checked. All of them hold - StatisticsResult: Ultimate Automizer benchmark data CFG has 5 procedures, 38 locations, 1 error locations. Started 1 CEGAR loops. VerificationResult: SAFE, OverallTime: 1.2s, OverallIterations: 1, TraceHistogramMax: 1, AutomataDifference: 0.3s, DeadEndRemovalTime: 0.0s, HoareAnnotationTime: 0.0s, InitialAbstractionConstructionTime: 0.0s, HoareTripleCheckerStatistics: 23 SDtfs, 25 SDslu, 87 SDs, 0 SdLazy, 106 SolverSat, 3 SolverUnsat, 0 SolverUnknown, 0 SolverNotchecked, 0.1s Time, PredicateUnifierStatistics: 0 DeclaredPredicates, 16 GetRequests, 4 SyntacticMatches, 0 SemanticMatches, 12 ConstructedPredicates, 0 IntricatePredicates, 0 DeprecatedPredicates, 8 ImplicationChecksByTransitivity, 0.2s Time, 0.0s BasicInterpolantAutomatonTime, BiggestAbstraction: size=38occurred in iteration=0, traceCheckStatistics: No data available, InterpolantConsolidationStatistics: No data available, PathInvariantsStatistics: No data available, 0/0 InterpolantCoveringCapability, TotalInterpolationStatistics: No data available, 0.0s DumpTime, AutomataMinimizationStatistics: 0.0s AutomataMinimizationTime, 1 MinimizatonAttempts, 0 StatesRemovedByMinimization, 0 NontrivialMinimizations, HoareAnnotationStatistics: 0.0s HoareAnnotationTime, 8 LocationsWithAnnotation, 8 PreInvPairs, 8 NumberOfFragments, 19 HoareAnnotationTreeSize, 8 FomulaSimplifications, 0 FormulaSimplificationTreeSizeReduction, 0.0s HoareSimplificationTime, 8 FomulaSimplificationsInter, 16 FormulaSimplificationTreeSizeReductionInter, 0.0s HoareSimplificationTimeInter, RefinementEngineStatistics: TRACE_CHECK: 0.0s SsaConstructionTime, 0.0s SatisfiabilityAnalysisTime, 0.7s InterpolantComputationTime, 26 NumberOfCodeBlocks, 26 NumberOfCodeBlocksAsserted, 1 NumberOfCheckSat, 25 ConstructedInterpolants, 0 QuantifiedInterpolants, 2400 SizeOfPredicates, 0 NumberOfNonLiveVariables, 0 ConjunctsInSsa, 0 ConjunctsInUnsatCore, 1 InterpolantComputations, 1 PerfectInterpolantSequences, 0/0 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 correct! Received shutdown request...