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# AProVE Commit ID: 794c25de1cacf0d048858bcd21c9a779e1221865 marcel 20200619 unpublished dirty Termination w.r.t. Q of the given QTRS could be proven: (0) QTRS (1) DependencyPairsProof [EQUIVALENT, 0 ms] (2) QDP (3) DependencyGraphProof [EQUIVALENT, 0 ms] (4) QDP (5) QDPOrderProof [EQUIVALENT, 160 ms] (6) QDP (7) DependencyGraphProof [EQUIVALENT, 0 ms] (8) QDP (9) UsableRulesProof [EQUIVALENT, 0 ms] (10) QDP (11) QDPOrderProof [EQUIVALENT, 0 ms] (12) QDP (13) PisEmptyProof [EQUIVALENT, 0 ms] (14) YES ---------------------------------------- (0) Obligation: Q restricted rewrite system: The TRS R consists of the following rules: a(a(x1)) -> b(b(b(c(x1)))) b(c(b(x1))) -> a(b(c(x1))) Q is empty. ---------------------------------------- (1) DependencyPairsProof (EQUIVALENT) Using Dependency Pairs [AG00,LPAR04] we result in the following initial DP problem. ---------------------------------------- (2) Obligation: Q DP problem: The TRS P consists of the following rules: A(a(x1)) -> B(b(b(c(x1)))) A(a(x1)) -> B(b(c(x1))) A(a(x1)) -> B(c(x1)) B(c(b(x1))) -> A(b(c(x1))) B(c(b(x1))) -> B(c(x1)) The TRS R consists of the following rules: a(a(x1)) -> b(b(b(c(x1)))) b(c(b(x1))) -> a(b(c(x1))) Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (3) DependencyGraphProof (EQUIVALENT) The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 1 SCC with 2 less nodes. ---------------------------------------- (4) Obligation: Q DP problem: The TRS P consists of the following rules: A(a(x1)) -> B(c(x1)) B(c(b(x1))) -> A(b(c(x1))) B(c(b(x1))) -> B(c(x1)) The TRS R consists of the following rules: a(a(x1)) -> b(b(b(c(x1)))) b(c(b(x1))) -> a(b(c(x1))) Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (5) QDPOrderProof (EQUIVALENT) We use the reduction pair processor [LPAR04,JAR06]. The following pairs can be oriented strictly and are deleted. A(a(x1)) -> B(c(x1)) The remaining pairs can at least be oriented weakly. Used ordering: Matrix interpretation [MATRO] with arctic natural numbers [ARCTIC]: <<< POL(A(x_1)) = [[-I]] + [[0A, -I, 0A]] * x_1 >>> <<< POL(a(x_1)) = [[0A], [0A], [1A]] + [[0A, -I, 0A], [0A, 0A, 1A], [1A, 0A, 0A]] * x_1 >>> <<< POL(B(x_1)) = [[-I]] + [[0A, 0A, -I]] * x_1 >>> <<< POL(c(x_1)) = [[0A], [0A], [0A]] + [[0A, -I, -I], [0A, -I, -I], [0A, 0A, -I]] * x_1 >>> <<< POL(b(x_1)) = [[0A], [1A], [0A]] + [[0A, 0A, -I], [1A, 0A, 0A], [0A, 0A, 0A]] * x_1 >>> The following usable rules [FROCOS05] with respect to the argument filtering of the ordering [JAR06] were oriented: b(c(b(x1))) -> a(b(c(x1))) a(a(x1)) -> b(b(b(c(x1)))) ---------------------------------------- (6) Obligation: Q DP problem: The TRS P consists of the following rules: B(c(b(x1))) -> A(b(c(x1))) B(c(b(x1))) -> B(c(x1)) The TRS R consists of the following rules: a(a(x1)) -> b(b(b(c(x1)))) b(c(b(x1))) -> a(b(c(x1))) Q is empty. 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: B(c(b(x1))) -> B(c(x1)) The TRS R consists of the following rules: a(a(x1)) -> b(b(b(c(x1)))) b(c(b(x1))) -> a(b(c(x1))) Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (9) 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. ---------------------------------------- (10) Obligation: Q DP problem: The TRS P consists of the following rules: B(c(b(x1))) -> B(c(x1)) R is empty. Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (11) QDPOrderProof (EQUIVALENT) We use the reduction pair processor [LPAR04,JAR06]. The following pairs can be oriented strictly and are deleted. B(c(b(x1))) -> B(c(x1)) The remaining pairs can at least be oriented weakly. Used ordering: Polynomial interpretation [POLO]: POL(B(x_1)) = x_1 POL(b(x_1)) = 1 + x_1 POL(c(x_1)) = x_1 The following usable rules [FROCOS05] with respect to the argument filtering of the ordering [JAR06] were oriented: none ---------------------------------------- (12) Obligation: Q DP problem: P is empty. R is empty. Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (13) PisEmptyProof (EQUIVALENT) The TRS P is empty. Hence, there is no (P,Q,R) chain. ---------------------------------------- (14) YES