YES 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# AProVE Commit ID: 794c25de1cacf0d048858bcd21c9a779e1221865 marcel 20200619 unpublished dirty Termination w.r.t. Q of the given QTRS could be proven: (0) QTRS (1) QTRSRRRProof [EQUIVALENT, 57 ms] (2) QTRS (3) Overlay + Local Confluence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) RFCMatchBoundsDPProof [EQUIVALENT, 0 ms] (12) YES ---------------------------------------- (0) Obligation: Q restricted rewrite system: The TRS R consists of the following rules: f(a) -> g(h(a)) h(g(x)) -> g(h(f(x))) k(x, h(x), a) -> h(x) k(f(x), y, x) -> f(x) Q is empty. ---------------------------------------- (1) QTRSRRRProof (EQUIVALENT) Used ordering: Polynomial interpretation [POLO]: POL(a) = 0 POL(f(x_1)) = x_1 POL(g(x_1)) = 2*x_1 POL(h(x_1)) = x_1 POL(k(x_1, x_2, x_3)) = 2 + 2*x_1 + 2*x_2 + x_3 With this ordering the following rules can be removed by the rule removal processor [LPAR04] because they are oriented strictly: k(x, h(x), a) -> h(x) k(f(x), y, x) -> f(x) ---------------------------------------- (2) Obligation: Q restricted rewrite system: The TRS R consists of the following rules: f(a) -> g(h(a)) h(g(x)) -> g(h(f(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(a) -> g(h(a)) h(g(x)) -> g(h(f(x))) The set Q consists of the following terms: f(a) h(g(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: F(a) -> H(a) H(g(x)) -> H(f(x)) H(g(x)) -> F(x) The TRS R consists of the following rules: f(a) -> g(h(a)) h(g(x)) -> g(h(f(x))) The set Q consists of the following terms: f(a) h(g(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 2 less nodes. ---------------------------------------- (8) Obligation: Q DP problem: The TRS P consists of the following rules: H(g(x)) -> H(f(x)) The TRS R consists of the following rules: f(a) -> g(h(a)) h(g(x)) -> g(h(f(x))) The set Q consists of the following terms: f(a) h(g(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: H(g(x)) -> H(f(x)) The TRS R consists of the following rules: f(a) -> g(h(a)) The set Q consists of the following terms: f(a) h(g(x0)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (11) RFCMatchBoundsDPProof (EQUIVALENT) Finiteness of the DP problem can be shown by a matchbound of 1. As the DP problem is minimal we only have to initialize the certificate graph by the rules of P: H(g(x)) -> H(f(x)) To find matches we regarded all rules of R and P: f(a) -> g(h(a)) H(g(x)) -> H(f(x)) The certificate found is represented by the following graph. The certificate consists of the following enumerated nodes: 31, 32, 33, 34, 35, 36 Node 31 is start node and node 32 is final node. Those nodes are connected through the following edges: * 31 to 33 labelled H_1(0)* 31 to 36 labelled H_1(1)* 32 to 32 labelled #_1(0)* 33 to 32 labelled f_1(0)* 33 to 34 labelled g_1(1)* 34 to 35 labelled h_1(1)* 35 to 32 labelled a(1)* 36 to 34 labelled f_1(1) ---------------------------------------- (12) YES