/export/starexec/sandbox/solver/bin/starexec_run_standard /export/starexec/sandbox/benchmark/theBenchmark.xml /export/starexec/sandbox/output/output_files -------------------------------------------------------------------------------- MAYBE proof of /export/starexec/sandbox/benchmark/theBenchmark.xml # AProVE Commit ID: 794c25de1cacf0d048858bcd21c9a779e1221865 marcel 20200619 unpublished dirty Quasi decreasingness of the given CTRS could not be shown: (0) CTRS (1) CTRSToQTRSProof [SOUND, 0 ms] (2) QTRS (3) QTRSRRRProof [EQUIVALENT, 33 ms] (4) QTRS (5) AAECC Innermost [EQUIVALENT, 0 ms] (6) QTRS (7) DependencyPairsProof [EQUIVALENT, 0 ms] (8) QDP (9) UsableRulesProof [EQUIVALENT, 0 ms] (10) QDP (11) QReductionProof [EQUIVALENT, 0 ms] (12) QDP (13) TransformationProof [EQUIVALENT, 0 ms] (14) QDP (15) NonTerminationLoopProof [COMPLETE, 0 ms] (16) NO ---------------------------------------- (0) Obligation: Conditional term rewrite system: The TRS R consists of the following rules: odd(0) -> false even(0) -> true eq(x, x) -> eq(T, T) The conditional TRS C consists of the following conditional rules: odd(s(x)) -> true <= eq(even(x), true) -> eq(T, T) odd(s(x)) -> false <= eq(even(x), false) -> eq(T, T) even(s(x)) -> true <= eq(odd(x), true) -> eq(T, T) even(s(x)) -> false <= eq(odd(x), false) -> eq(T, T) ---------------------------------------- (1) CTRSToQTRSProof (SOUND) The conditional rules have been transormed into unconditional rules according to [CTRS,AAECCNOC]. ---------------------------------------- (2) Obligation: Q restricted rewrite system: The TRS R consists of the following rules: odd(s(x)) -> U1(eq(even(x), true)) U1(eq(T, T)) -> true odd(s(x)) -> U2(eq(even(x), false)) U2(eq(T, T)) -> false even(s(x)) -> U3(eq(odd(x), true)) U3(eq(T, T)) -> true even(s(x)) -> U4(eq(odd(x), false)) U4(eq(T, T)) -> false odd(0) -> false even(0) -> true eq(x, x) -> eq(T, T) Q is empty. ---------------------------------------- (3) QTRSRRRProof (EQUIVALENT) Used ordering: Knuth-Bendix order [KBO] with precedence:odd_1 > U1_1 > true > eq_2 > 0 > even_1 > U4_1 > U3_1 > U2_1 > false > s_1 > T and weight map: true=4 T=1 false=3 0=1 odd_1=5 s_1=7 U1_1=2 even_1=6 U2_1=1 U3_1=3 U4_1=1 eq_2=0 The variable weight is 1With this ordering the following rules can be removed by the rule removal processor [LPAR04] because they are oriented strictly: odd(s(x)) -> U1(eq(even(x), true)) U1(eq(T, T)) -> true odd(s(x)) -> U2(eq(even(x), false)) U2(eq(T, T)) -> false even(s(x)) -> U3(eq(odd(x), true)) U3(eq(T, T)) -> true even(s(x)) -> U4(eq(odd(x), false)) U4(eq(T, T)) -> false odd(0) -> false even(0) -> true ---------------------------------------- (4) Obligation: Q restricted rewrite system: The TRS R consists of the following rules: eq(x, x) -> eq(T, T) Q is empty. ---------------------------------------- (5) AAECC Innermost (EQUIVALENT) We have applied [NOC,AAECCNOC] to switch to innermost. The TRS R 1 is none The TRS R 2 is eq(x, x) -> eq(T, T) The signature Sigma is {eq_2} ---------------------------------------- (6) Obligation: Q restricted rewrite system: The TRS R consists of the following rules: eq(x, x) -> eq(T, T) The set Q consists of the following terms: eq(x0, x0) ---------------------------------------- (7) DependencyPairsProof (EQUIVALENT) Using Dependency Pairs [AG00,LPAR04] we result in the following initial DP problem. ---------------------------------------- (8) Obligation: Q DP problem: The TRS P consists of the following rules: EQ(x, x) -> EQ(T, T) The TRS R consists of the following rules: eq(x, x) -> eq(T, T) The set Q consists of the following terms: eq(x0, x0) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (9) UsableRulesProof (EQUIVALENT) As all Q-normal forms are R-normal forms we are in the innermost case. Hence, by the usable rules processor [LPAR04] we can delete all non-usable rules [FROCOS05] from R. ---------------------------------------- (10) Obligation: Q DP problem: The TRS P consists of the following rules: EQ(x, x) -> EQ(T, T) R is empty. The set Q consists of the following terms: eq(x0, x0) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (11) QReductionProof (EQUIVALENT) We deleted the following terms from Q as each root-symbol of these terms does neither occur in P nor in R.[THIEMANN]. eq(x0, x0) ---------------------------------------- (12) Obligation: Q DP problem: The TRS P consists of the following rules: EQ(x, x) -> EQ(T, T) R is empty. Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (13) TransformationProof (EQUIVALENT) By instantiating [LPAR04] the rule EQ(x, x) -> EQ(T, T) we obtained the following new rules [LPAR04]: (EQ(T, T) -> EQ(T, T),EQ(T, T) -> EQ(T, T)) ---------------------------------------- (14) Obligation: Q DP problem: The TRS P consists of the following rules: EQ(T, T) -> EQ(T, T) R is empty. Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (15) NonTerminationLoopProof (COMPLETE) We used the non-termination processor [FROCOS05] to show that the DP problem is infinite. Found a loop by semiunifying a rule from P directly. s = EQ(T, T) evaluates to t =EQ(T, T) Thus s starts an infinite chain as s semiunifies with t with the following substitutions: * Matcher: [ ] * Semiunifier: [ ] -------------------------------------------------------------------------------- Rewriting sequence The DP semiunifies directly so there is only one rewrite step from EQ(T, T) to EQ(T, T). ---------------------------------------- (16) NO