NO proof of /export/starexec/sandbox2/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# AProVE Commit ID: 794c25de1cacf0d048858bcd21c9a779e1221865 marcel 20200619 unpublished dirty Termination w.r.t. Q of the given QTRS could be disproven: (0) QTRS (1) QTRSRRRProof [EQUIVALENT, 0 ms] (2) QTRS (3) Overlay + Local Confluence [EQUIVALENT, 0 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) TransformationProof [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: f(X) -> if(X, c, f(true)) if(true, X, Y) -> X if(false, X, Y) -> Y Q is empty. ---------------------------------------- (1) QTRSRRRProof (EQUIVALENT) Used ordering: Polynomial interpretation [POLO]: POL(c) = 0 POL(f(x_1)) = 2*x_1 POL(false) = 2 POL(if(x_1, x_2, x_3)) = 2*x_1 + 2*x_2 + 2*x_3 POL(true) = 0 With this ordering the following rules can be removed by the rule removal processor [LPAR04] because they are oriented strictly: if(false, X, Y) -> Y ---------------------------------------- (2) Obligation: Q restricted rewrite system: The TRS R consists of the following rules: f(X) -> if(X, c, f(true)) if(true, X, Y) -> X Q is empty. ---------------------------------------- (3) Overlay + Local Confluence (EQUIVALENT) The TRS is overlay and locally confluent. By [NOC] we can switch to innermost. ---------------------------------------- (4) Obligation: Q restricted rewrite system: The TRS R consists of the following rules: f(X) -> if(X, c, f(true)) if(true, X, Y) -> X The set Q consists of the following terms: f(x0) if(true, x0, x1) ---------------------------------------- (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: F(X) -> IF(X, c, f(true)) F(X) -> F(true) The TRS R consists of the following rules: f(X) -> if(X, c, f(true)) if(true, X, Y) -> X The set Q consists of the following terms: f(x0) if(true, x0, x1) 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: F(X) -> F(true) The TRS R consists of the following rules: f(X) -> if(X, c, f(true)) if(true, X, Y) -> X The set Q consists of the following terms: f(x0) if(true, x0, x1) 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: F(X) -> F(true) R is empty. The set Q consists of the following terms: f(x0) if(true, x0, x1) 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]. f(x0) if(true, x0, x1) ---------------------------------------- (12) Obligation: Q DP problem: The TRS P consists of the following rules: F(X) -> F(true) R is empty. Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (13) TransformationProof (EQUIVALENT) By instantiating [LPAR04] the rule F(X) -> F(true) we obtained the following new rules [LPAR04]: (F(true) -> F(true),F(true) -> F(true)) ---------------------------------------- (14) Obligation: Q DP problem: The TRS P consists of the following rules: F(true) -> F(true) 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 = F(true) evaluates to t =F(true) 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 F(true) to F(true). ---------------------------------------- (16) NO