NO proof of /export/starexec/sandbox/benchmark/theBenchmark.xml # AProVE Commit ID: 794c25de1cacf0d048858bcd21c9a779e1221865 marcel 20200619 unpublished dirty Termination w.r.t. Q of the given QTRS could be disproven: (0) QTRS (1) QTRS Reverse [EQUIVALENT, 0 ms] (2) QTRS (3) AAECC Innermost [EQUIVALENT, 4 ms] (4) QTRS (5) DependencyPairsProof [EQUIVALENT, 0 ms] (6) QDP (7) DependencyGraphProof [EQUIVALENT, 0 ms] (8) QDP (9) UsableRulesProof [EQUIVALENT, 0 ms] (10) QDP (11) QReductionProof [EQUIVALENT, 0 ms] (12) QDP (13) MNOCProof [EQUIVALENT, 0 ms] (14) QDP (15) NonTerminationLoopProof [COMPLETE, 0 ms] (16) NO ---------------------------------------- (0) Obligation: Q restricted rewrite system: The TRS R consists of the following rules: g(X) -> h(X) c -> d h(d) -> g(c) Q is empty. ---------------------------------------- (1) QTRS Reverse (EQUIVALENT) We applied the QTRS Reverse Processor [REVERSE]. ---------------------------------------- (2) Obligation: Q restricted rewrite system: The TRS R consists of the following rules: g(X) -> h(X) c'(x) -> d'(x) d'(h(x)) -> c'(g(x)) Q is empty. ---------------------------------------- (3) AAECC Innermost (EQUIVALENT) We have applied [NOC,AAECCNOC] to switch to innermost. The TRS R 1 is g(X) -> h(X) The TRS R 2 is c'(x) -> d'(x) d'(h(x)) -> c'(g(x)) The signature Sigma is {c'_1, d'_1} ---------------------------------------- (4) Obligation: Q restricted rewrite system: The TRS R consists of the following rules: g(X) -> h(X) c'(x) -> d'(x) d'(h(x)) -> c'(g(x)) The set Q consists of the following terms: g(x0) c'(x0) d'(h(x0)) ---------------------------------------- (5) DependencyPairsProof (EQUIVALENT) Using Dependency Pairs [AG00,LPAR04] we result in the following initial DP problem. ---------------------------------------- (6) Obligation: Q DP problem: The TRS P consists of the following rules: C'(x) -> D'(x) D'(h(x)) -> C'(g(x)) D'(h(x)) -> G(x) The TRS R consists of the following rules: g(X) -> h(X) c'(x) -> d'(x) d'(h(x)) -> c'(g(x)) The set Q consists of the following terms: g(x0) c'(x0) d'(h(x0)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (7) DependencyGraphProof (EQUIVALENT) The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 1 SCC with 1 less node. ---------------------------------------- (8) Obligation: Q DP problem: The TRS P consists of the following rules: D'(h(x)) -> C'(g(x)) C'(x) -> D'(x) The TRS R consists of the following rules: g(X) -> h(X) c'(x) -> d'(x) d'(h(x)) -> c'(g(x)) The set Q consists of the following terms: g(x0) c'(x0) d'(h(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: D'(h(x)) -> C'(g(x)) C'(x) -> D'(x) The TRS R consists of the following rules: g(X) -> h(X) The set Q consists of the following terms: g(x0) c'(x0) d'(h(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]. c'(x0) d'(h(x0)) ---------------------------------------- (12) Obligation: Q DP problem: The TRS P consists of the following rules: D'(h(x)) -> C'(g(x)) C'(x) -> D'(x) The TRS R consists of the following rules: g(X) -> h(X) The set Q consists of the following terms: g(x0) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (13) MNOCProof (EQUIVALENT) We use the modular non-overlap check [FROCOS05] to decrease Q to the empty set. ---------------------------------------- (14) Obligation: Q DP problem: The TRS P consists of the following rules: D'(h(x)) -> C'(g(x)) C'(x) -> D'(x) The TRS R consists of the following rules: g(X) -> h(X) Q is empty. We have to consider all (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 narrowing to the left: s = C'(g(X)) evaluates to t =C'(g(X)) Thus s starts an infinite chain as s semiunifies with t with the following substitutions: * Matcher: [ ] * Semiunifier: [ ] -------------------------------------------------------------------------------- Rewriting sequence C'(g(X)) -> C'(h(X)) with rule g(X') -> h(X') at position [0] and matcher [X' / X] C'(h(X)) -> D'(h(X)) with rule C'(x') -> D'(x') at position [] and matcher [x' / h(X)] D'(h(X)) -> C'(g(X)) with rule D'(h(x)) -> C'(g(x)) Now applying the matcher to the start term leads to a term which is equal to the last term in the rewriting sequence All these steps are and every following step will be a correct step w.r.t to Q. ---------------------------------------- (16) NO