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# AProVE Commit ID: 794c25de1cacf0d048858bcd21c9a779e1221865 marcel 20200619 unpublished dirty Termination w.r.t. Q of the given QTRS could be disproven: (0) QTRS (1) QTRSRRRProof [EQUIVALENT, 66 ms] (2) QTRS (3) DependencyPairsProof [EQUIVALENT, 0 ms] (4) QDP (5) DependencyGraphProof [EQUIVALENT, 0 ms] (6) AND (7) QDP (8) UsableRulesProof [EQUIVALENT, 0 ms] (9) QDP (10) QDPSizeChangeProof [EQUIVALENT, 0 ms] (11) YES (12) QDP (13) NonLoopProof [COMPLETE, 0 ms] (14) NO ---------------------------------------- (0) Obligation: Q restricted rewrite system: The TRS R consists of the following rules: h(X, Z) -> f(X, s(X), Z) f(X, Y, g(X, Y)) -> h(0, g(X, Y)) g(0, Y) -> 0 g(X, s(Y)) -> g(X, Y) Q is empty. ---------------------------------------- (1) QTRSRRRProof (EQUIVALENT) Used ordering: Polynomial interpretation [POLO]: POL(0) = 0 POL(f(x_1, x_2, x_3)) = x_1 + x_2 + x_3 POL(g(x_1, x_2)) = 2 + 2*x_1 + x_2 POL(h(x_1, x_2)) = 2*x_1 + x_2 POL(s(x_1)) = x_1 With this ordering the following rules can be removed by the rule removal processor [LPAR04] because they are oriented strictly: g(0, Y) -> 0 ---------------------------------------- (2) Obligation: Q restricted rewrite system: The TRS R consists of the following rules: h(X, Z) -> f(X, s(X), Z) f(X, Y, g(X, Y)) -> h(0, g(X, Y)) g(X, s(Y)) -> g(X, Y) Q is empty. ---------------------------------------- (3) DependencyPairsProof (EQUIVALENT) Using Dependency Pairs [AG00,LPAR04] we result in the following initial DP problem. ---------------------------------------- (4) Obligation: Q DP problem: The TRS P consists of the following rules: H(X, Z) -> F(X, s(X), Z) F(X, Y, g(X, Y)) -> H(0, g(X, Y)) G(X, s(Y)) -> G(X, Y) The TRS R consists of the following rules: h(X, Z) -> f(X, s(X), Z) f(X, Y, g(X, Y)) -> h(0, g(X, Y)) g(X, s(Y)) -> g(X, Y) Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (5) DependencyGraphProof (EQUIVALENT) The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 2 SCCs. ---------------------------------------- (6) Complex Obligation (AND) ---------------------------------------- (7) Obligation: Q DP problem: The TRS P consists of the following rules: G(X, s(Y)) -> G(X, Y) The TRS R consists of the following rules: h(X, Z) -> f(X, s(X), Z) f(X, Y, g(X, Y)) -> h(0, g(X, Y)) g(X, s(Y)) -> g(X, Y) Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (8) UsableRulesProof (EQUIVALENT) We can use the usable rules and reduction pair processor [LPAR04] with the Ce-compatible extension of the polynomial order that maps every function symbol to the sum of its arguments. Then, we can delete all non-usable rules [FROCOS05] from R. ---------------------------------------- (9) Obligation: Q DP problem: The TRS P consists of the following rules: G(X, s(Y)) -> G(X, Y) R is empty. Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (10) QDPSizeChangeProof (EQUIVALENT) By using the subterm criterion [SUBTERM_CRITERION] together with the size-change analysis [AAECC05] we have proven that there are no infinite chains for this DP problem. From the DPs we obtained the following set of size-change graphs: *G(X, s(Y)) -> G(X, Y) The graph contains the following edges 1 >= 1, 2 > 2 ---------------------------------------- (11) YES ---------------------------------------- (12) Obligation: Q DP problem: The TRS P consists of the following rules: F(X, Y, g(X, Y)) -> H(0, g(X, Y)) H(X, Z) -> F(X, s(X), Z) The TRS R consists of the following rules: h(X, Z) -> f(X, s(X), Z) f(X, Y, g(X, Y)) -> h(0, g(X, Y)) g(X, s(Y)) -> g(X, Y) Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (13) NonLoopProof (COMPLETE) By Theorem 8 [NONLOOP] we deduce infiniteness of the QDP. We apply the theorem with m = 1, b = 0, σ' = [ ], and μ' = [ ] on the rule H(0, g(0, s(0)))[ ]^n[x0 / 0] -> H(0, g(0, s(0)))[ ]^n[x0 / 0] This rule is correct for the QDP as the following derivation shows: H(0, g(0, s(0)))[ ]^n[x0 / 0] -> H(0, g(0, s(0)))[ ]^n[x0 / 0] by Equivalency by Simplifying Mu with mu1: [x0 / 0] mu2: [x0 / 0] intermediate steps: Equiv Smu (lhs) - Instantiate mu - Instantiation H(x1, g(x1, s(x1)))[ ]^n[ ] -> H(0, g(x1, s(x1)))[ ]^n[ ] by Narrowing at position: [] intermediate steps: Instantiation - Instantiation H(X, Z)[ ]^n[ ] -> F(X, s(X), Z)[ ]^n[ ] by Rule from TRS P intermediate steps: Instantiation - Instantiation - Instantiation - Instantiation F(X, Y, g(X, Y))[ ]^n[ ] -> H(0, g(X, Y))[ ]^n[ ] by Rule from TRS P ---------------------------------------- (14) NO