YES 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# AProVE Commit ID: 794c25de1cacf0d048858bcd21c9a779e1221865 marcel 20200619 unpublished dirty Termination w.r.t. Q of the given QTRS could be proven: (0) QTRS (1) DependencyPairsProof [EQUIVALENT, 7 ms] (2) QDP (3) DependencyGraphProof [EQUIVALENT, 0 ms] (4) QDP (5) QDPOrderProof [EQUIVALENT, 80 ms] (6) QDP (7) UsableRulesProof [EQUIVALENT, 1 ms] (8) QDP (9) QDPSizeChangeProof [EQUIVALENT, 0 ms] (10) YES ---------------------------------------- (0) Obligation: Q restricted rewrite system: The TRS R consists of the following rules: a(x1) -> b(x1) a(a(x1)) -> a(b(a(c(x1)))) c(b(b(x1))) -> a(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)) -> A(b(a(c(x1)))) A(a(x1)) -> A(c(x1)) A(a(x1)) -> C(x1) C(b(b(x1))) -> A(x1) The TRS R consists of the following rules: a(x1) -> b(x1) a(a(x1)) -> a(b(a(c(x1)))) c(b(b(x1))) -> a(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 1 less node. ---------------------------------------- (4) Obligation: Q DP problem: The TRS P consists of the following rules: A(a(x1)) -> C(x1) C(b(b(x1))) -> A(x1) A(a(x1)) -> A(c(x1)) The TRS R consists of the following rules: a(x1) -> b(x1) a(a(x1)) -> a(b(a(c(x1)))) c(b(b(x1))) -> a(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)) -> A(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)) = [[0A]] + [[0A, 0A, 0A]] * x_1 >>> <<< POL(a(x_1)) = [[1A], [1A], [0A]] + [[0A, 1A, 0A], [0A, 1A, 0A], [1A, 1A, 0A]] * x_1 >>> <<< POL(C(x_1)) = [[1A]] + [[0A, 0A, -I]] * x_1 >>> <<< POL(b(x_1)) = [[1A], [0A], [0A]] + [[0A, 0A, 0A], [0A, 0A, 0A], [1A, 1A, 0A]] * x_1 >>> <<< POL(c(x_1)) = [[0A], [0A], [-I]] + [[-I, 0A, -I], [-I, 0A, -I], [0A, -I, -I]] * x_1 >>> The following usable rules [FROCOS05] with respect to the argument filtering of the ordering [JAR06] were oriented: c(b(b(x1))) -> a(x1) a(a(x1)) -> a(b(a(c(x1)))) a(x1) -> b(x1) ---------------------------------------- (6) Obligation: Q DP problem: The TRS P consists of the following rules: A(a(x1)) -> C(x1) C(b(b(x1))) -> A(x1) The TRS R consists of the following rules: a(x1) -> b(x1) a(a(x1)) -> a(b(a(c(x1)))) c(b(b(x1))) -> a(x1) Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (7) 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. ---------------------------------------- (8) Obligation: Q DP problem: The TRS P consists of the following rules: A(a(x1)) -> C(x1) C(b(b(x1))) -> A(x1) R is empty. Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (9) 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: *C(b(b(x1))) -> A(x1) The graph contains the following edges 1 > 1 *A(a(x1)) -> C(x1) The graph contains the following edges 1 > 1 ---------------------------------------- (10) YES