java -Xmx8000000000 -Xss4m -jar ./plugins/org.eclipse.equinox.launcher_1.3.100.v20150511-1540.jar -data @noDefault -ultimatedata ./data -tc ../../../trunk/examples/toolchains/SifaC.xml -s ../../../trunk/examples/settings/default/automizer/svcomp-Reach-32bit-Automizer_Default.epf -i ../../../trunk/examples/svcomp/eca-rers2012/Problem05_label18.c -------------------------------------------------------------------------------- This is Ultimate 0.1.24-fab3c18 [2019-08-22 19:54:38,986 INFO L177 SettingsManager]: Resetting all preferences to default values... [2019-08-22 19:54:38,988 INFO L181 SettingsManager]: Resetting UltimateCore preferences to default values [2019-08-22 19:54:39,000 INFO L184 SettingsManager]: Ultimate Commandline Interface provides no preferences, ignoring... [2019-08-22 19:54:39,000 INFO L181 SettingsManager]: Resetting Boogie Preprocessor preferences to default values [2019-08-22 19:54:39,001 INFO L181 SettingsManager]: Resetting Boogie Procedure Inliner preferences to default values [2019-08-22 19:54:39,003 INFO L181 SettingsManager]: Resetting Abstract Interpretation preferences to default values [2019-08-22 19:54:39,005 INFO L181 SettingsManager]: Resetting LassoRanker preferences to default values [2019-08-22 19:54:39,006 INFO L181 SettingsManager]: Resetting Reaching Definitions preferences to default values [2019-08-22 19:54:39,007 INFO L181 SettingsManager]: Resetting SyntaxChecker preferences to default values [2019-08-22 19:54:39,008 INFO L181 SettingsManager]: Resetting Symbolic Interpretation preferences to default values [2019-08-22 19:54:39,009 INFO L184 SettingsManager]: Büchi Program Product provides no preferences, ignoring... [2019-08-22 19:54:39,009 INFO L181 SettingsManager]: Resetting LTL2Aut preferences to default values [2019-08-22 19:54:39,010 INFO L181 SettingsManager]: Resetting PEA to Boogie preferences to default values [2019-08-22 19:54:39,011 INFO L181 SettingsManager]: Resetting BlockEncodingV2 preferences to default values [2019-08-22 19:54:39,012 INFO L181 SettingsManager]: Resetting ChcToBoogie preferences to default values [2019-08-22 19:54:39,013 INFO L181 SettingsManager]: Resetting AutomataScriptInterpreter preferences to default values [2019-08-22 19:54:39,014 INFO L181 SettingsManager]: Resetting BuchiAutomizer preferences to default values [2019-08-22 19:54:39,016 INFO L181 SettingsManager]: Resetting CACSL2BoogieTranslator preferences to default values [2019-08-22 19:54:39,018 INFO L181 SettingsManager]: Resetting CodeCheck preferences to default values [2019-08-22 19:54:39,019 INFO L181 SettingsManager]: Resetting InvariantSynthesis preferences to default values [2019-08-22 19:54:39,020 INFO L181 SettingsManager]: Resetting RCFGBuilder preferences to default values [2019-08-22 19:54:39,021 INFO L181 SettingsManager]: Resetting Referee preferences to default values [2019-08-22 19:54:39,022 INFO L181 SettingsManager]: Resetting TraceAbstraction preferences to default values [2019-08-22 19:54:39,024 INFO L184 SettingsManager]: TraceAbstractionConcurrent provides no preferences, ignoring... [2019-08-22 19:54:39,024 INFO L184 SettingsManager]: TraceAbstractionWithAFAs provides no preferences, ignoring... [2019-08-22 19:54:39,024 INFO L181 SettingsManager]: Resetting TreeAutomizer preferences to default values [2019-08-22 19:54:39,025 INFO L181 SettingsManager]: Resetting IcfgToChc preferences to default values [2019-08-22 19:54:39,026 INFO L181 SettingsManager]: Resetting IcfgTransformer preferences to default values [2019-08-22 19:54:39,026 INFO L184 SettingsManager]: ReqToTest provides no preferences, ignoring... [2019-08-22 19:54:39,027 INFO L181 SettingsManager]: Resetting Boogie Printer preferences to default values [2019-08-22 19:54:39,027 INFO L181 SettingsManager]: Resetting ChcSmtPrinter preferences to default values [2019-08-22 19:54:39,028 INFO L181 SettingsManager]: Resetting ReqPrinter preferences to default values [2019-08-22 19:54:39,029 INFO L181 SettingsManager]: Resetting Witness Printer preferences to default values [2019-08-22 19:54:39,030 INFO L184 SettingsManager]: Boogie PL CUP Parser provides no preferences, ignoring... [2019-08-22 19:54:39,030 INFO L181 SettingsManager]: Resetting CDTParser preferences to default values [2019-08-22 19:54:39,031 INFO L184 SettingsManager]: AutomataScriptParser provides no preferences, ignoring... [2019-08-22 19:54:39,031 INFO L184 SettingsManager]: ReqParser provides no preferences, ignoring... [2019-08-22 19:54:39,031 INFO L181 SettingsManager]: Resetting SmtParser preferences to default values [2019-08-22 19:54:39,032 INFO L181 SettingsManager]: Resetting Witness Parser preferences to default values [2019-08-22 19:54:39,033 INFO L188 SettingsManager]: Finished resetting all preferences to default values... [2019-08-22 19:54:39,033 INFO L101 SettingsManager]: Beginning loading settings from /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/../../../trunk/examples/settings/default/automizer/svcomp-Reach-32bit-Automizer_Default.epf [2019-08-22 19:54:39,047 INFO L113 SettingsManager]: Loading preferences was successful [2019-08-22 19:54:39,047 INFO L115 SettingsManager]: Preferences different from defaults after loading the file: [2019-08-22 19:54:39,049 INFO L136 SettingsManager]: Preferences of BlockEncodingV2 differ from their defaults: [2019-08-22 19:54:39,049 INFO L138 SettingsManager]: * Create parallel compositions if possible=false [2019-08-22 19:54:39,049 INFO L138 SettingsManager]: * Use SBE=true [2019-08-22 19:54:39,049 INFO L136 SettingsManager]: Preferences of CACSL2BoogieTranslator differ from their defaults: [2019-08-22 19:54:39,049 INFO L138 SettingsManager]: * sizeof long=4 [2019-08-22 19:54:39,050 INFO L138 SettingsManager]: * Overapproximate operations on floating types=true [2019-08-22 19:54:39,050 INFO L138 SettingsManager]: * sizeof POINTER=4 [2019-08-22 19:54:39,050 INFO L138 SettingsManager]: * Check division by zero=IGNORE [2019-08-22 19:54:39,050 INFO L138 SettingsManager]: * Pointer to allocated memory at dereference=IGNORE [2019-08-22 19:54:39,050 INFO L138 SettingsManager]: * If two pointers are subtracted or compared they have the same base address=IGNORE [2019-08-22 19:54:39,051 INFO L138 SettingsManager]: * Check array bounds for arrays that are off heap=IGNORE [2019-08-22 19:54:39,051 INFO L138 SettingsManager]: * sizeof long double=12 [2019-08-22 19:54:39,051 INFO L138 SettingsManager]: * Check if freed pointer was valid=false [2019-08-22 19:54:39,051 INFO L138 SettingsManager]: * Use constant arrays=true [2019-08-22 19:54:39,051 INFO L138 SettingsManager]: * Pointer base address is valid at dereference=IGNORE [2019-08-22 19:54:39,052 INFO L136 SettingsManager]: Preferences of RCFGBuilder differ from their defaults: [2019-08-22 19:54:39,052 INFO L138 SettingsManager]: * Size of a code block=SequenceOfStatements [2019-08-22 19:54:39,052 INFO L138 SettingsManager]: * To the following directory=./dump/ [2019-08-22 19:54:39,052 INFO L138 SettingsManager]: * SMT solver=External_DefaultMode [2019-08-22 19:54:39,052 INFO L138 SettingsManager]: * Command for external solver=z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in -t:2000 [2019-08-22 19:54:39,053 INFO L136 SettingsManager]: Preferences of TraceAbstraction differ from their defaults: [2019-08-22 19:54:39,053 INFO L138 SettingsManager]: * Compute Interpolants along a Counterexample=FPandBP [2019-08-22 19:54:39,053 INFO L138 SettingsManager]: * Positions where we compute the Hoare Annotation=LoopsAndPotentialCycles [2019-08-22 19:54:39,053 INFO L138 SettingsManager]: * Trace refinement strategy=CAMEL [2019-08-22 19:54:39,053 INFO L138 SettingsManager]: * SMT solver=External_ModelsAndUnsatCoreMode [2019-08-22 19:54:39,054 INFO L138 SettingsManager]: * Command for external solver=z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in [2019-08-22 19:54:39,054 INFO L138 SettingsManager]: * Compute Hoare Annotation of negated interpolant automaton, abstraction and CFG=true [2019-08-22 19:54:39,085 INFO L81 nceAwareModelManager]: Repository-Root is: /tmp [2019-08-22 19:54:39,098 INFO L258 ainManager$Toolchain]: [Toolchain 1]: Applicable parser(s) successfully (re)initialized [2019-08-22 19:54:39,102 INFO L214 ainManager$Toolchain]: [Toolchain 1]: Toolchain selected. [2019-08-22 19:54:39,104 INFO L271 PluginConnector]: Initializing CDTParser... [2019-08-22 19:54:39,104 INFO L275 PluginConnector]: CDTParser initialized [2019-08-22 19:54:39,105 INFO L428 ainManager$Toolchain]: [Toolchain 1]: Parsing single file: /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/../../../trunk/examples/svcomp/eca-rers2012/Problem05_label18.c [2019-08-22 19:54:39,166 INFO L220 CDTParser]: Created temporary CDT project at /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/data/2859c7b12/7b7d43e7af4f4bbea4fd941bc11d6d84/FLAG60762a16d [2019-08-22 19:54:40,128 INFO L306 CDTParser]: Found 1 translation units. [2019-08-22 19:54:40,130 INFO L160 CDTParser]: Scanning /storage/repos/ultimate/trunk/examples/svcomp/eca-rers2012/Problem05_label18.c [2019-08-22 19:54:40,170 INFO L349 CDTParser]: About to delete temporary CDT project at /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/data/2859c7b12/7b7d43e7af4f4bbea4fd941bc11d6d84/FLAG60762a16d [2019-08-22 19:54:40,443 INFO L357 CDTParser]: Successfully deleted /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/data/2859c7b12/7b7d43e7af4f4bbea4fd941bc11d6d84 [2019-08-22 19:54:40,454 INFO L296 ainManager$Toolchain]: ####################### [Toolchain 1] ####################### [2019-08-22 19:54:40,455 INFO L131 ToolchainWalker]: Walking toolchain with 4 elements. [2019-08-22 19:54:40,456 INFO L113 PluginConnector]: ------------------------CACSL2BoogieTranslator---------------------------- [2019-08-22 19:54:40,457 INFO L271 PluginConnector]: Initializing CACSL2BoogieTranslator... [2019-08-22 19:54:40,460 INFO L275 PluginConnector]: CACSL2BoogieTranslator initialized [2019-08-22 19:54:40,461 INFO L185 PluginConnector]: Executing the observer ACSLObjectContainerObserver from plugin CACSL2BoogieTranslator for "CDTParser AST 22.08 07:54:40" (1/1) ... [2019-08-22 19:54:40,464 INFO L205 PluginConnector]: Invalid model from CACSL2BoogieTranslator for observer de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator.ACSLObjectContainerObserver@47e91111 and model type de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 22.08 07:54:40, skipping insertion in model container [2019-08-22 19:54:40,464 INFO L185 PluginConnector]: Executing the observer CACSL2BoogieTranslatorObserver from plugin CACSL2BoogieTranslator for "CDTParser AST 22.08 07:54:40" (1/1) ... [2019-08-22 19:54:40,471 INFO L142 MainTranslator]: Starting translation in SV-COMP mode [2019-08-22 19:54:40,737 INFO L173 MainTranslator]: Built tables and reachable declarations [2019-08-22 19:54:43,030 INFO L206 PostProcessor]: Analyzing one entry point: main [2019-08-22 19:54:43,035 INFO L188 MainTranslator]: Completed pre-run [2019-08-22 19:54:44,127 INFO L206 PostProcessor]: Analyzing one entry point: main [2019-08-22 19:54:44,192 INFO L192 MainTranslator]: Completed translation [2019-08-22 19:54:44,193 INFO L202 PluginConnector]: Adding new model de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 22.08 07:54:44 WrapperNode [2019-08-22 19:54:44,193 INFO L132 PluginConnector]: ------------------------ END CACSL2BoogieTranslator---------------------------- [2019-08-22 19:54:44,194 INFO L113 PluginConnector]: ------------------------Boogie Preprocessor---------------------------- [2019-08-22 19:54:44,194 INFO L271 PluginConnector]: Initializing Boogie Preprocessor... [2019-08-22 19:54:44,194 INFO L275 PluginConnector]: Boogie Preprocessor initialized [2019-08-22 19:54:44,209 INFO L185 PluginConnector]: Executing the observer EnsureBoogieModelObserver from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 22.08 07:54:44" (1/1) ... [2019-08-22 19:54:44,209 INFO L185 PluginConnector]: Executing the observer TypeChecker from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 22.08 07:54:44" (1/1) ... [2019-08-22 19:54:44,298 INFO L185 PluginConnector]: Executing the observer ConstExpander from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 22.08 07:54:44" (1/1) ... [2019-08-22 19:54:44,299 INFO L185 PluginConnector]: Executing the observer StructExpander from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 22.08 07:54:44" (1/1) ... [2019-08-22 19:54:44,465 INFO L185 PluginConnector]: Executing the observer UnstructureCode from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 22.08 07:54:44" (1/1) ... [2019-08-22 19:54:44,514 INFO L185 PluginConnector]: Executing the observer FunctionInliner from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 22.08 07:54:44" (1/1) ... [2019-08-22 19:54:44,580 INFO L185 PluginConnector]: Executing the observer BoogieSymbolTableConstructor from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 22.08 07:54:44" (1/1) ... [2019-08-22 19:54:44,636 INFO L132 PluginConnector]: ------------------------ END Boogie Preprocessor---------------------------- [2019-08-22 19:54:44,636 INFO L113 PluginConnector]: ------------------------RCFGBuilder---------------------------- [2019-08-22 19:54:44,637 INFO L271 PluginConnector]: Initializing RCFGBuilder... [2019-08-22 19:54:44,637 INFO L275 PluginConnector]: RCFGBuilder initialized [2019-08-22 19:54:44,638 INFO L185 PluginConnector]: Executing the observer RCFGBuilderObserver from plugin RCFGBuilder for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 22.08 07:54:44" (1/1) ... No working directory specified, using /storage/repos/ultimate/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 [2019-08-22 19:54:44,713 INFO L138 BoogieDeclarations]: Found implementation of procedure ULTIMATE.init [2019-08-22 19:54:44,713 INFO L138 BoogieDeclarations]: Found implementation of procedure ULTIMATE.start [2019-08-22 19:54:44,713 INFO L138 BoogieDeclarations]: Found implementation of procedure calculate_output [2019-08-22 19:54:44,714 INFO L138 BoogieDeclarations]: Found implementation of procedure calculate_output2 [2019-08-22 19:54:44,714 INFO L138 BoogieDeclarations]: Found implementation of procedure calculate_output3 [2019-08-22 19:54:44,714 INFO L138 BoogieDeclarations]: Found implementation of procedure calculate_output4 [2019-08-22 19:54:44,714 INFO L138 BoogieDeclarations]: Found implementation of procedure calculate_output5 [2019-08-22 19:54:44,714 INFO L138 BoogieDeclarations]: Found implementation of procedure calculate_output6 [2019-08-22 19:54:44,714 INFO L138 BoogieDeclarations]: Found implementation of procedure calculate_output7 [2019-08-22 19:54:44,715 INFO L138 BoogieDeclarations]: Found implementation of procedure calculate_output8 [2019-08-22 19:54:44,715 INFO L138 BoogieDeclarations]: Found implementation of procedure main [2019-08-22 19:54:44,715 INFO L130 BoogieDeclarations]: Found specification of procedure calculate_output [2019-08-22 19:54:44,716 INFO L130 BoogieDeclarations]: Found specification of procedure calculate_output2 [2019-08-22 19:54:44,716 INFO L130 BoogieDeclarations]: Found specification of procedure calculate_output3 [2019-08-22 19:54:44,717 INFO L130 BoogieDeclarations]: Found specification of procedure calculate_output4 [2019-08-22 19:54:44,717 INFO L130 BoogieDeclarations]: Found specification of procedure calculate_output5 [2019-08-22 19:54:44,718 INFO L130 BoogieDeclarations]: Found specification of procedure calculate_output6 [2019-08-22 19:54:44,718 INFO L130 BoogieDeclarations]: Found specification of procedure calculate_output7 [2019-08-22 19:54:44,718 INFO L130 BoogieDeclarations]: Found specification of procedure calculate_output8 [2019-08-22 19:54:44,719 INFO L130 BoogieDeclarations]: Found specification of procedure __VERIFIER_error [2019-08-22 19:54:44,719 INFO L130 BoogieDeclarations]: Found specification of procedure __VERIFIER_nondet_int [2019-08-22 19:54:44,720 INFO L130 BoogieDeclarations]: Found specification of procedure exit [2019-08-22 19:54:44,720 INFO L130 BoogieDeclarations]: Found specification of procedure main [2019-08-22 19:54:44,720 INFO L130 BoogieDeclarations]: Found specification of procedure ULTIMATE.init [2019-08-22 19:54:44,720 INFO L130 BoogieDeclarations]: Found specification of procedure ULTIMATE.start [2019-08-22 19:54:53,198 INFO L278 CfgBuilder]: Using the 1 location(s) as analysis (start of procedure ULTIMATE.start) [2019-08-22 19:54:53,198 INFO L283 CfgBuilder]: Removed 1 assume(true) statements. [2019-08-22 19:54:53,202 INFO L202 PluginConnector]: Adding new model de.uni_freiburg.informatik.ultimate.plugins.generator.rcfgbuilder CFG 22.08 07:54:53 BoogieIcfgContainer [2019-08-22 19:54:53,202 INFO L132 PluginConnector]: ------------------------ END RCFGBuilder---------------------------- [2019-08-22 19:54:53,203 INFO L113 PluginConnector]: ------------------------Symbolic Interpretation---------------------------- [2019-08-22 19:54:53,203 INFO L271 PluginConnector]: Initializing Symbolic Interpretation... [2019-08-22 19:54:53,203 INFO L275 PluginConnector]: Symbolic Interpretation initialized [2019-08-22 19:54:53,205 INFO L185 PluginConnector]: Executing the observer SymbolicInterpretationObserver from plugin Symbolic Interpretation for "de.uni_freiburg.informatik.ultimate.plugins.generator.rcfgbuilder CFG 22.08 07:54:53" (1/1) ... [2019-08-22 19:54:53,241 INFO L148 IcfgInterpreter]: Started Sifa with 1 locations of interest [2019-08-22 19:54:53,246 INFO L155 IcfgInterpreter]: Building call graph [2019-08-22 19:54:53,276 INFO L160 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2019-08-22 19:54:53,286 INFO L165 IcfgInterpreter]: Starting interpretation [2019-08-22 19:54:53,288 INFO L185 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 [2019-08-22 19:54:53,376 INFO L185 IcfgInterpreter]: Interpreting procedure main with input of size 71 [2019-08-22 19:54:57,471 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 2 terms [2019-08-22 19:54:58,888 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 2 terms [2019-08-22 19:54:58,890 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 2 terms [2019-08-22 19:54:58,894 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 2 terms [2019-08-22 19:54:58,895 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 2 terms [2019-08-22 19:54:59,267 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 7 terms [2019-08-22 19:54:59,509 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 3 terms [2019-08-22 19:55:00,423 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 3 terms [2019-08-22 19:55:02,322 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 3 terms [2019-08-22 19:55:07,180 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 3 terms [2019-08-22 19:55:07,181 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 7 terms [2019-08-22 19:55:07,182 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 7 terms [2019-08-22 19:55:07,183 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 7 terms [2019-08-22 19:55:07,877 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 3 terms [2019-08-22 19:55:09,963 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 8 terms [2019-08-22 19:55:11,791 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 8 terms [2019-08-22 19:55:11,792 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 2 terms [2019-08-22 19:55:11,792 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 2 terms [2019-08-22 19:55:11,793 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 2 terms [2019-08-22 19:55:11,795 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 2 terms [2019-08-22 19:55:11,800 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 2 terms [2019-08-22 19:55:11,801 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 2 terms [2019-08-22 19:55:11,803 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 2 terms [2019-08-22 19:55:17,309 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 7 terms [2019-08-22 19:55:37,015 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 2 terms [2019-08-22 19:55:37,016 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 8 terms [2019-08-22 19:55:39,022 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 7 terms