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_label23.c -------------------------------------------------------------------------------- This is Ultimate 0.1.24-fab3c18 [2019-08-22 19:55:09,061 INFO L177 SettingsManager]: Resetting all preferences to default values... [2019-08-22 19:55:09,064 INFO L181 SettingsManager]: Resetting UltimateCore preferences to default values [2019-08-22 19:55:09,082 INFO L184 SettingsManager]: Ultimate Commandline Interface provides no preferences, ignoring... [2019-08-22 19:55:09,083 INFO L181 SettingsManager]: Resetting Boogie Preprocessor preferences to default values [2019-08-22 19:55:09,084 INFO L181 SettingsManager]: Resetting Boogie Procedure Inliner preferences to default values [2019-08-22 19:55:09,086 INFO L181 SettingsManager]: Resetting Abstract Interpretation preferences to default values [2019-08-22 19:55:09,099 INFO L181 SettingsManager]: Resetting LassoRanker preferences to default values [2019-08-22 19:55:09,101 INFO L181 SettingsManager]: Resetting Reaching Definitions preferences to default values [2019-08-22 19:55:09,102 INFO L181 SettingsManager]: Resetting SyntaxChecker preferences to default values [2019-08-22 19:55:09,106 INFO L181 SettingsManager]: Resetting Symbolic Interpretation preferences to default values [2019-08-22 19:55:09,108 INFO L184 SettingsManager]: Büchi Program Product provides no preferences, ignoring... [2019-08-22 19:55:09,109 INFO L181 SettingsManager]: Resetting LTL2Aut preferences to default values [2019-08-22 19:55:09,113 INFO L181 SettingsManager]: Resetting PEA to Boogie preferences to default values [2019-08-22 19:55:09,115 INFO L181 SettingsManager]: Resetting BlockEncodingV2 preferences to default values [2019-08-22 19:55:09,118 INFO L181 SettingsManager]: Resetting ChcToBoogie preferences to default values [2019-08-22 19:55:09,119 INFO L181 SettingsManager]: Resetting AutomataScriptInterpreter preferences to default values [2019-08-22 19:55:09,122 INFO L181 SettingsManager]: Resetting BuchiAutomizer preferences to default values [2019-08-22 19:55:09,125 INFO L181 SettingsManager]: Resetting CACSL2BoogieTranslator preferences to default values [2019-08-22 19:55:09,130 INFO L181 SettingsManager]: Resetting CodeCheck preferences to default values [2019-08-22 19:55:09,134 INFO L181 SettingsManager]: Resetting InvariantSynthesis preferences to default values [2019-08-22 19:55:09,136 INFO L181 SettingsManager]: Resetting RCFGBuilder preferences to default values [2019-08-22 19:55:09,137 INFO L181 SettingsManager]: Resetting Referee preferences to default values [2019-08-22 19:55:09,140 INFO L181 SettingsManager]: Resetting TraceAbstraction preferences to default values [2019-08-22 19:55:09,142 INFO L184 SettingsManager]: TraceAbstractionConcurrent provides no preferences, ignoring... [2019-08-22 19:55:09,143 INFO L184 SettingsManager]: TraceAbstractionWithAFAs provides no preferences, ignoring... [2019-08-22 19:55:09,143 INFO L181 SettingsManager]: Resetting TreeAutomizer preferences to default values [2019-08-22 19:55:09,145 INFO L181 SettingsManager]: Resetting IcfgToChc preferences to default values [2019-08-22 19:55:09,146 INFO L181 SettingsManager]: Resetting IcfgTransformer preferences to default values [2019-08-22 19:55:09,147 INFO L184 SettingsManager]: ReqToTest provides no preferences, ignoring... [2019-08-22 19:55:09,147 INFO L181 SettingsManager]: Resetting Boogie Printer preferences to default values [2019-08-22 19:55:09,149 INFO L181 SettingsManager]: Resetting ChcSmtPrinter preferences to default values [2019-08-22 19:55:09,150 INFO L181 SettingsManager]: Resetting ReqPrinter preferences to default values [2019-08-22 19:55:09,150 INFO L181 SettingsManager]: Resetting Witness Printer preferences to default values [2019-08-22 19:55:09,152 INFO L184 SettingsManager]: Boogie PL CUP Parser provides no preferences, ignoring... [2019-08-22 19:55:09,153 INFO L181 SettingsManager]: Resetting CDTParser preferences to default values [2019-08-22 19:55:09,153 INFO L184 SettingsManager]: AutomataScriptParser provides no preferences, ignoring... [2019-08-22 19:55:09,153 INFO L184 SettingsManager]: ReqParser provides no preferences, ignoring... [2019-08-22 19:55:09,154 INFO L181 SettingsManager]: Resetting SmtParser preferences to default values [2019-08-22 19:55:09,154 INFO L181 SettingsManager]: Resetting Witness Parser preferences to default values [2019-08-22 19:55:09,155 INFO L188 SettingsManager]: Finished resetting all preferences to default values... [2019-08-22 19:55:09,157 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 19:55:09,175 INFO L113 SettingsManager]: Loading preferences was successful [2019-08-22 19:55:09,176 INFO L115 SettingsManager]: Preferences different from defaults after loading the file: [2019-08-22 19:55:09,178 INFO L136 SettingsManager]: Preferences of BlockEncodingV2 differ from their defaults: [2019-08-22 19:55:09,178 INFO L138 SettingsManager]: * Create parallel compositions if possible=false [2019-08-22 19:55:09,178 INFO L138 SettingsManager]: * Use SBE=true [2019-08-22 19:55:09,179 INFO L136 SettingsManager]: Preferences of CACSL2BoogieTranslator differ from their defaults: [2019-08-22 19:55:09,179 INFO L138 SettingsManager]: * sizeof long=4 [2019-08-22 19:55:09,179 INFO L138 SettingsManager]: * Overapproximate operations on floating types=true [2019-08-22 19:55:09,179 INFO L138 SettingsManager]: * sizeof POINTER=4 [2019-08-22 19:55:09,179 INFO L138 SettingsManager]: * Check division by zero=IGNORE [2019-08-22 19:55:09,181 INFO L138 SettingsManager]: * Pointer to allocated memory at dereference=IGNORE [2019-08-22 19:55:09,181 INFO L138 SettingsManager]: * If two pointers are subtracted or compared they have the same base address=IGNORE [2019-08-22 19:55:09,181 INFO L138 SettingsManager]: * Check array bounds for arrays that are off heap=IGNORE [2019-08-22 19:55:09,181 INFO L138 SettingsManager]: * sizeof long double=12 [2019-08-22 19:55:09,182 INFO L138 SettingsManager]: * Check if freed pointer was valid=false [2019-08-22 19:55:09,182 INFO L138 SettingsManager]: * Use constant arrays=true [2019-08-22 19:55:09,182 INFO L138 SettingsManager]: * Pointer base address is valid at dereference=IGNORE [2019-08-22 19:55:09,182 INFO L136 SettingsManager]: Preferences of RCFGBuilder differ from their defaults: [2019-08-22 19:55:09,183 INFO L138 SettingsManager]: * Size of a code block=SequenceOfStatements [2019-08-22 19:55:09,183 INFO L138 SettingsManager]: * To the following directory=./dump/ [2019-08-22 19:55:09,183 INFO L138 SettingsManager]: * SMT solver=External_DefaultMode [2019-08-22 19:55:09,183 INFO L138 SettingsManager]: * Command for external solver=z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in -t:2000 [2019-08-22 19:55:09,183 INFO L136 SettingsManager]: Preferences of TraceAbstraction differ from their defaults: [2019-08-22 19:55:09,184 INFO L138 SettingsManager]: * Compute Interpolants along a Counterexample=FPandBP [2019-08-22 19:55:09,184 INFO L138 SettingsManager]: * Positions where we compute the Hoare Annotation=LoopsAndPotentialCycles [2019-08-22 19:55:09,184 INFO L138 SettingsManager]: * Trace refinement strategy=CAMEL [2019-08-22 19:55:09,184 INFO L138 SettingsManager]: * SMT solver=External_ModelsAndUnsatCoreMode [2019-08-22 19:55:09,185 INFO L138 SettingsManager]: * Command for external solver=z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in [2019-08-22 19:55:09,185 INFO L138 SettingsManager]: * Compute Hoare Annotation of negated interpolant automaton, abstraction and CFG=true [2019-08-22 19:55:09,234 INFO L81 nceAwareModelManager]: Repository-Root is: /tmp [2019-08-22 19:55:09,252 INFO L258 ainManager$Toolchain]: [Toolchain 1]: Applicable parser(s) successfully (re)initialized [2019-08-22 19:55:09,256 INFO L214 ainManager$Toolchain]: [Toolchain 1]: Toolchain selected. [2019-08-22 19:55:09,259 INFO L271 PluginConnector]: Initializing CDTParser... [2019-08-22 19:55:09,259 INFO L275 PluginConnector]: CDTParser initialized [2019-08-22 19:55:09,260 INFO L428 ainManager$Toolchain]: [Toolchain 1]: Parsing single file: /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/../../../trunk/examples/svcomp/eca-rers2012/Problem05_label23.c [2019-08-22 19:55:09,318 INFO L220 CDTParser]: Created temporary CDT project at /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/data/706b95195/1c01e8d5ace44f6eaceef7ea8b171ee4/FLAGf03d2c44e [2019-08-22 19:55:10,138 INFO L306 CDTParser]: Found 1 translation units. [2019-08-22 19:55:10,139 INFO L160 CDTParser]: Scanning /storage/repos/ultimate/trunk/examples/svcomp/eca-rers2012/Problem05_label23.c [2019-08-22 19:55:10,171 INFO L349 CDTParser]: About to delete temporary CDT project at /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/data/706b95195/1c01e8d5ace44f6eaceef7ea8b171ee4/FLAGf03d2c44e [2019-08-22 19:55:10,628 INFO L357 CDTParser]: Successfully deleted /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/data/706b95195/1c01e8d5ace44f6eaceef7ea8b171ee4 [2019-08-22 19:55:10,637 INFO L296 ainManager$Toolchain]: ####################### [Toolchain 1] ####################### [2019-08-22 19:55:10,638 INFO L131 ToolchainWalker]: Walking toolchain with 4 elements. [2019-08-22 19:55:10,639 INFO L113 PluginConnector]: ------------------------CACSL2BoogieTranslator---------------------------- [2019-08-22 19:55:10,639 INFO L271 PluginConnector]: Initializing CACSL2BoogieTranslator... [2019-08-22 19:55:10,642 INFO L275 PluginConnector]: CACSL2BoogieTranslator initialized [2019-08-22 19:55:10,643 INFO L185 PluginConnector]: Executing the observer ACSLObjectContainerObserver from plugin CACSL2BoogieTranslator for "CDTParser AST 22.08 07:55:10" (1/1) ... [2019-08-22 19:55:10,646 INFO L205 PluginConnector]: Invalid model from CACSL2BoogieTranslator for observer de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator.ACSLObjectContainerObserver@6454d8e4 and model type de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 22.08 07:55:10, skipping insertion in model container [2019-08-22 19:55:10,646 INFO L185 PluginConnector]: Executing the observer CACSL2BoogieTranslatorObserver from plugin CACSL2BoogieTranslator for "CDTParser AST 22.08 07:55:10" (1/1) ... [2019-08-22 19:55:10,653 INFO L142 MainTranslator]: Starting translation in SV-COMP mode [2019-08-22 19:55:10,867 INFO L173 MainTranslator]: Built tables and reachable declarations [2019-08-22 19:55:13,132 INFO L206 PostProcessor]: Analyzing one entry point: main [2019-08-22 19:55:13,144 INFO L188 MainTranslator]: Completed pre-run [2019-08-22 19:55:14,344 INFO L206 PostProcessor]: Analyzing one entry point: main [2019-08-22 19:55:14,406 INFO L192 MainTranslator]: Completed translation [2019-08-22 19:55:14,407 INFO L202 PluginConnector]: Adding new model de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 22.08 07:55:14 WrapperNode [2019-08-22 19:55:14,407 INFO L132 PluginConnector]: ------------------------ END CACSL2BoogieTranslator---------------------------- [2019-08-22 19:55:14,408 INFO L113 PluginConnector]: ------------------------Boogie Preprocessor---------------------------- [2019-08-22 19:55:14,408 INFO L271 PluginConnector]: Initializing Boogie Preprocessor... [2019-08-22 19:55:14,408 INFO L275 PluginConnector]: Boogie Preprocessor initialized [2019-08-22 19:55:14,422 INFO L185 PluginConnector]: Executing the observer EnsureBoogieModelObserver from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 22.08 07:55:14" (1/1) ... [2019-08-22 19:55:14,422 INFO L185 PluginConnector]: Executing the observer TypeChecker from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 22.08 07:55:14" (1/1) ... [2019-08-22 19:55:14,494 INFO L185 PluginConnector]: Executing the observer ConstExpander from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 22.08 07:55:14" (1/1) ... [2019-08-22 19:55:14,494 INFO L185 PluginConnector]: Executing the observer StructExpander from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 22.08 07:55:14" (1/1) ... [2019-08-22 19:55:14,629 INFO L185 PluginConnector]: Executing the observer UnstructureCode from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 22.08 07:55:14" (1/1) ... [2019-08-22 19:55:14,674 INFO L185 PluginConnector]: Executing the observer FunctionInliner from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 22.08 07:55:14" (1/1) ... [2019-08-22 19:55:14,715 INFO L185 PluginConnector]: Executing the observer BoogieSymbolTableConstructor from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 22.08 07:55:14" (1/1) ... [2019-08-22 19:55:14,768 INFO L132 PluginConnector]: ------------------------ END Boogie Preprocessor---------------------------- [2019-08-22 19:55:14,768 INFO L113 PluginConnector]: ------------------------RCFGBuilder---------------------------- [2019-08-22 19:55:14,769 INFO L271 PluginConnector]: Initializing RCFGBuilder... [2019-08-22 19:55:14,769 INFO L275 PluginConnector]: RCFGBuilder initialized [2019-08-22 19:55:14,770 INFO L185 PluginConnector]: Executing the observer RCFGBuilderObserver from plugin RCFGBuilder for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 22.08 07:55:14" (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 19:55:14,842 INFO L138 BoogieDeclarations]: Found implementation of procedure ULTIMATE.init [2019-08-22 19:55:14,842 INFO L138 BoogieDeclarations]: Found implementation of procedure ULTIMATE.start [2019-08-22 19:55:14,843 INFO L138 BoogieDeclarations]: Found implementation of procedure calculate_output [2019-08-22 19:55:14,843 INFO L138 BoogieDeclarations]: Found implementation of procedure calculate_output2 [2019-08-22 19:55:14,843 INFO L138 BoogieDeclarations]: Found implementation of procedure calculate_output3 [2019-08-22 19:55:14,843 INFO L138 BoogieDeclarations]: Found implementation of procedure calculate_output4 [2019-08-22 19:55:14,843 INFO L138 BoogieDeclarations]: Found implementation of procedure calculate_output5 [2019-08-22 19:55:14,844 INFO L138 BoogieDeclarations]: Found implementation of procedure calculate_output6 [2019-08-22 19:55:14,844 INFO L138 BoogieDeclarations]: Found implementation of procedure calculate_output7 [2019-08-22 19:55:14,844 INFO L138 BoogieDeclarations]: Found implementation of procedure calculate_output8 [2019-08-22 19:55:14,844 INFO L138 BoogieDeclarations]: Found implementation of procedure main [2019-08-22 19:55:14,844 INFO L130 BoogieDeclarations]: Found specification of procedure calculate_output [2019-08-22 19:55:14,844 INFO L130 BoogieDeclarations]: Found specification of procedure calculate_output2 [2019-08-22 19:55:14,845 INFO L130 BoogieDeclarations]: Found specification of procedure calculate_output3 [2019-08-22 19:55:14,845 INFO L130 BoogieDeclarations]: Found specification of procedure calculate_output4 [2019-08-22 19:55:14,845 INFO L130 BoogieDeclarations]: Found specification of procedure calculate_output5 [2019-08-22 19:55:14,845 INFO L130 BoogieDeclarations]: Found specification of procedure calculate_output6 [2019-08-22 19:55:14,845 INFO L130 BoogieDeclarations]: Found specification of procedure calculate_output7 [2019-08-22 19:55:14,846 INFO L130 BoogieDeclarations]: Found specification of procedure calculate_output8 [2019-08-22 19:55:14,846 INFO L130 BoogieDeclarations]: Found specification of procedure __VERIFIER_error [2019-08-22 19:55:14,846 INFO L130 BoogieDeclarations]: Found specification of procedure __VERIFIER_nondet_int [2019-08-22 19:55:14,846 INFO L130 BoogieDeclarations]: Found specification of procedure exit [2019-08-22 19:55:14,846 INFO L130 BoogieDeclarations]: Found specification of procedure main [2019-08-22 19:55:14,847 INFO L130 BoogieDeclarations]: Found specification of procedure ULTIMATE.init [2019-08-22 19:55:14,847 INFO L130 BoogieDeclarations]: Found specification of procedure ULTIMATE.start [2019-08-22 19:55:22,714 INFO L278 CfgBuilder]: Using the 1 location(s) as analysis (start of procedure ULTIMATE.start) [2019-08-22 19:55:22,714 INFO L283 CfgBuilder]: Removed 1 assume(true) statements. [2019-08-22 19:55:22,717 INFO L202 PluginConnector]: Adding new model de.uni_freiburg.informatik.ultimate.plugins.generator.rcfgbuilder CFG 22.08 07:55:22 BoogieIcfgContainer [2019-08-22 19:55:22,717 INFO L132 PluginConnector]: ------------------------ END RCFGBuilder---------------------------- [2019-08-22 19:55:22,717 INFO L113 PluginConnector]: ------------------------Symbolic Interpretation---------------------------- [2019-08-22 19:55:22,717 INFO L271 PluginConnector]: Initializing Symbolic Interpretation... [2019-08-22 19:55:22,718 INFO L275 PluginConnector]: Symbolic Interpretation initialized [2019-08-22 19:55:22,719 INFO L185 PluginConnector]: Executing the observer SymbolicInterpretationObserver from plugin Symbolic Interpretation for "de.uni_freiburg.informatik.ultimate.plugins.generator.rcfgbuilder CFG 22.08 07:55:22" (1/1) ... [2019-08-22 19:55:22,731 INFO L148 IcfgInterpreter]: Started Sifa with 1 locations of interest [2019-08-22 19:55:22,733 INFO L155 IcfgInterpreter]: Building call graph [2019-08-22 19:55:22,752 INFO L160 IcfgInterpreter]: Initial procedures are [ULTIMATE.start] [2019-08-22 19:55:22,760 INFO L165 IcfgInterpreter]: Starting interpretation [2019-08-22 19:55:22,762 INFO L185 IcfgInterpreter]: Interpreting procedure ULTIMATE.start with input of size 1 [2019-08-22 19:55:22,834 INFO L185 IcfgInterpreter]: Interpreting procedure main with input of size 71 [2019-08-22 19:55:26,708 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 2 terms [2019-08-22 19:55:28,070 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 2 terms [2019-08-22 19:55:28,072 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 2 terms [2019-08-22 19:55:28,075 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 2 terms [2019-08-22 19:55:28,076 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 2 terms [2019-08-22 19:55:28,302 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 7 terms [2019-08-22 19:55:28,567 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 3 terms [2019-08-22 19:55:29,491 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 3 terms [2019-08-22 19:55:31,232 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 3 terms [2019-08-22 19:55:35,921 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 3 terms [2019-08-22 19:55:35,922 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 7 terms [2019-08-22 19:55:35,923 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 7 terms [2019-08-22 19:55:35,924 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 7 terms [2019-08-22 19:55:36,583 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 3 terms [2019-08-22 19:55:38,590 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 8 terms [2019-08-22 19:55:40,343 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 8 terms [2019-08-22 19:55:40,344 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 2 terms [2019-08-22 19:55:40,345 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 2 terms [2019-08-22 19:55:40,345 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 2 terms [2019-08-22 19:55:40,348 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 2 terms [2019-08-22 19:55:40,350 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 2 terms [2019-08-22 19:55:40,350 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 2 terms [2019-08-22 19:55:40,353 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 2 terms [2019-08-22 19:55:45,694 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 7 terms [2019-08-22 19:56:04,832 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 2 terms [2019-08-22 19:56:04,833 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 8 terms [2019-08-22 19:56:06,811 INFO L319 QuantifierPusher]: Applying distributivity, recursing on 7 terms