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# AProVE Commit ID: 794c25de1cacf0d048858bcd21c9a779e1221865 marcel 20200619 unpublished dirty Termination w.r.t. Q of the given QTRS could be proven: (0) QTRS (1) DependencyPairsProof [EQUIVALENT, 15 ms] (2) QDP (3) DependencyGraphProof [EQUIVALENT, 0 ms] (4) AND (5) QDP (6) UsableRulesProof [EQUIVALENT, 0 ms] (7) QDP (8) QDPOrderProof [EQUIVALENT, 31 ms] (9) QDP (10) DependencyGraphProof [EQUIVALENT, 0 ms] (11) TRUE (12) QDP (13) MNOCProof [EQUIVALENT, 0 ms] (14) QDP (15) UsableRulesProof [EQUIVALENT, 0 ms] (16) QDP (17) QReductionProof [EQUIVALENT, 0 ms] (18) QDP (19) QDPOrderProof [EQUIVALENT, 35 ms] (20) QDP (21) PisEmptyProof [EQUIVALENT, 0 ms] (22) YES ---------------------------------------- (0) Obligation: Q restricted rewrite system: The TRS R consists of the following rules: b(a(a(x1))) -> a(b(c(x1))) c(a(x1)) -> a(c(x1)) c(b(x1)) -> b(a(x1)) L(a(a(x1))) -> L(a(b(c(x1)))) c(R(x1)) -> b(a(R(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: B(a(a(x1))) -> B(c(x1)) B(a(a(x1))) -> C(x1) C(a(x1)) -> C(x1) C(b(x1)) -> B(a(x1)) L^1(a(a(x1))) -> L^1(a(b(c(x1)))) L^1(a(a(x1))) -> B(c(x1)) L^1(a(a(x1))) -> C(x1) C(R(x1)) -> B(a(R(x1))) The TRS R consists of the following rules: b(a(a(x1))) -> a(b(c(x1))) c(a(x1)) -> a(c(x1)) c(b(x1)) -> b(a(x1)) L(a(a(x1))) -> L(a(b(c(x1)))) c(R(x1)) -> b(a(R(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 2 SCCs with 3 less nodes. ---------------------------------------- (4) Complex Obligation (AND) ---------------------------------------- (5) Obligation: Q DP problem: The TRS P consists of the following rules: B(a(a(x1))) -> C(x1) C(a(x1)) -> C(x1) C(b(x1)) -> B(a(x1)) B(a(a(x1))) -> B(c(x1)) The TRS R consists of the following rules: b(a(a(x1))) -> a(b(c(x1))) c(a(x1)) -> a(c(x1)) c(b(x1)) -> b(a(x1)) L(a(a(x1))) -> L(a(b(c(x1)))) c(R(x1)) -> b(a(R(x1))) Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (6) 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. ---------------------------------------- (7) Obligation: Q DP problem: The TRS P consists of the following rules: B(a(a(x1))) -> C(x1) C(a(x1)) -> C(x1) C(b(x1)) -> B(a(x1)) B(a(a(x1))) -> B(c(x1)) The TRS R consists of the following rules: c(a(x1)) -> a(c(x1)) c(b(x1)) -> b(a(x1)) c(R(x1)) -> b(a(R(x1))) b(a(a(x1))) -> a(b(c(x1))) Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (8) QDPOrderProof (EQUIVALENT) We use the reduction pair processor [LPAR04,JAR06]. The following pairs can be oriented strictly and are deleted. B(a(a(x1))) -> C(x1) C(a(x1)) -> C(x1) B(a(a(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(C(x_1)) = 1 + x_1 POL(R(x_1)) = x_1 POL(a(x_1)) = 1 + x_1 POL(b(x_1)) = x_1 POL(c(x_1)) = 1 + x_1 The following usable rules [FROCOS05] with respect to the argument filtering of the ordering [JAR06] were oriented: c(a(x1)) -> a(c(x1)) c(b(x1)) -> b(a(x1)) c(R(x1)) -> b(a(R(x1))) b(a(a(x1))) -> a(b(c(x1))) ---------------------------------------- (9) Obligation: Q DP problem: The TRS P consists of the following rules: C(b(x1)) -> B(a(x1)) The TRS R consists of the following rules: c(a(x1)) -> a(c(x1)) c(b(x1)) -> b(a(x1)) c(R(x1)) -> b(a(R(x1))) b(a(a(x1))) -> a(b(c(x1))) Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (10) DependencyGraphProof (EQUIVALENT) The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 0 SCCs with 1 less node. ---------------------------------------- (11) TRUE ---------------------------------------- (12) Obligation: Q DP problem: The TRS P consists of the following rules: L^1(a(a(x1))) -> L^1(a(b(c(x1)))) The TRS R consists of the following rules: b(a(a(x1))) -> a(b(c(x1))) c(a(x1)) -> a(c(x1)) c(b(x1)) -> b(a(x1)) L(a(a(x1))) -> L(a(b(c(x1)))) c(R(x1)) -> b(a(R(x1))) Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (13) MNOCProof (EQUIVALENT) We use the modular non-overlap check [LPAR04] to enlarge Q to all left-hand sides of R. ---------------------------------------- (14) Obligation: Q DP problem: The TRS P consists of the following rules: L^1(a(a(x1))) -> L^1(a(b(c(x1)))) The TRS R consists of the following rules: b(a(a(x1))) -> a(b(c(x1))) c(a(x1)) -> a(c(x1)) c(b(x1)) -> b(a(x1)) L(a(a(x1))) -> L(a(b(c(x1)))) c(R(x1)) -> b(a(R(x1))) The set Q consists of the following terms: b(a(a(x0))) c(a(x0)) c(b(x0)) L(a(a(x0))) c(R(x0)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (15) 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. ---------------------------------------- (16) Obligation: Q DP problem: The TRS P consists of the following rules: L^1(a(a(x1))) -> L^1(a(b(c(x1)))) The TRS R consists of the following rules: c(a(x1)) -> a(c(x1)) c(b(x1)) -> b(a(x1)) c(R(x1)) -> b(a(R(x1))) b(a(a(x1))) -> a(b(c(x1))) The set Q consists of the following terms: b(a(a(x0))) c(a(x0)) c(b(x0)) L(a(a(x0))) c(R(x0)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (17) 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]. L(a(a(x0))) ---------------------------------------- (18) Obligation: Q DP problem: The TRS P consists of the following rules: L^1(a(a(x1))) -> L^1(a(b(c(x1)))) The TRS R consists of the following rules: c(a(x1)) -> a(c(x1)) c(b(x1)) -> b(a(x1)) c(R(x1)) -> b(a(R(x1))) b(a(a(x1))) -> a(b(c(x1))) The set Q consists of the following terms: b(a(a(x0))) c(a(x0)) c(b(x0)) c(R(x0)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (19) QDPOrderProof (EQUIVALENT) We use the reduction pair processor [LPAR04,JAR06]. The following pairs can be oriented strictly and are deleted. L^1(a(a(x1))) -> L^1(a(b(c(x1)))) The remaining pairs can at least be oriented weakly. Used ordering: Polynomial Order [NEGPOLO,POLO] with Interpretation: POL( L^1_1(x_1) ) = 2x_1 + 2 POL( a_1(x_1) ) = x_1 + 1 POL( b_1(x_1) ) = max{0, x_1 - 1} POL( c_1(x_1) ) = x_1 + 1 POL( R_1(x_1) ) = 0 The following usable rules [FROCOS05] with respect to the argument filtering of the ordering [JAR06] were oriented: c(a(x1)) -> a(c(x1)) c(b(x1)) -> b(a(x1)) c(R(x1)) -> b(a(R(x1))) b(a(a(x1))) -> a(b(c(x1))) ---------------------------------------- (20) Obligation: Q DP problem: P is empty. The TRS R consists of the following rules: c(a(x1)) -> a(c(x1)) c(b(x1)) -> b(a(x1)) c(R(x1)) -> b(a(R(x1))) b(a(a(x1))) -> a(b(c(x1))) The set Q consists of the following terms: b(a(a(x0))) c(a(x0)) c(b(x0)) c(R(x0)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (21) PisEmptyProof (EQUIVALENT) The TRS P is empty. Hence, there is no (P,Q,R) chain. ---------------------------------------- (22) YES