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# AProVE Commit ID: 794c25de1cacf0d048858bcd21c9a779e1221865 marcel 20200619 unpublished dirty Termination w.r.t. Q of the given QTRS could be proven: (0) QTRS (1) Overlay + Local Confluence [EQUIVALENT, 0 ms] (2) QTRS (3) DependencyPairsProof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) QReductionProof [EQUIVALENT, 1 ms] (11) QDP (12) QDPSizeChangeProof [EQUIVALENT, 0 ms] (13) YES (14) QDP (15) UsableRulesProof [EQUIVALENT, 0 ms] (16) QDP (17) QReductionProof [EQUIVALENT, 1 ms] (18) QDP (19) QDPSizeChangeProof [EQUIVALENT, 0 ms] (20) YES (21) QDP (22) UsableRulesProof [EQUIVALENT, 0 ms] (23) QDP (24) QReductionProof [EQUIVALENT, 0 ms] (25) QDP (26) QDPOrderProof [EQUIVALENT, 33 ms] (27) QDP (28) PisEmptyProof [EQUIVALENT, 0 ms] (29) YES ---------------------------------------- (0) Obligation: Q restricted rewrite system: The TRS R consists of the following rules: eq(0, 0) -> true eq(0, s(X)) -> false eq(s(X), 0) -> false eq(s(X), s(Y)) -> eq(X, Y) rm(N, nil) -> nil rm(N, add(M, X)) -> ifrm(eq(N, M), N, add(M, X)) ifrm(true, N, add(M, X)) -> rm(N, X) ifrm(false, N, add(M, X)) -> add(M, rm(N, X)) purge(nil) -> nil purge(add(N, X)) -> add(N, purge(rm(N, X))) Q is empty. ---------------------------------------- (1) Overlay + Local Confluence (EQUIVALENT) The TRS is overlay and locally confluent. By [NOC] we can switch to innermost. ---------------------------------------- (2) Obligation: Q restricted rewrite system: The TRS R consists of the following rules: eq(0, 0) -> true eq(0, s(X)) -> false eq(s(X), 0) -> false eq(s(X), s(Y)) -> eq(X, Y) rm(N, nil) -> nil rm(N, add(M, X)) -> ifrm(eq(N, M), N, add(M, X)) ifrm(true, N, add(M, X)) -> rm(N, X) ifrm(false, N, add(M, X)) -> add(M, rm(N, X)) purge(nil) -> nil purge(add(N, X)) -> add(N, purge(rm(N, X))) The set Q consists of the following terms: eq(0, 0) eq(0, s(x0)) eq(s(x0), 0) eq(s(x0), s(x1)) rm(x0, nil) rm(x0, add(x1, x2)) ifrm(true, x0, add(x1, x2)) ifrm(false, x0, add(x1, x2)) purge(nil) purge(add(x0, x1)) ---------------------------------------- (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: EQ(s(X), s(Y)) -> EQ(X, Y) RM(N, add(M, X)) -> IFRM(eq(N, M), N, add(M, X)) RM(N, add(M, X)) -> EQ(N, M) IFRM(true, N, add(M, X)) -> RM(N, X) IFRM(false, N, add(M, X)) -> RM(N, X) PURGE(add(N, X)) -> PURGE(rm(N, X)) PURGE(add(N, X)) -> RM(N, X) The TRS R consists of the following rules: eq(0, 0) -> true eq(0, s(X)) -> false eq(s(X), 0) -> false eq(s(X), s(Y)) -> eq(X, Y) rm(N, nil) -> nil rm(N, add(M, X)) -> ifrm(eq(N, M), N, add(M, X)) ifrm(true, N, add(M, X)) -> rm(N, X) ifrm(false, N, add(M, X)) -> add(M, rm(N, X)) purge(nil) -> nil purge(add(N, X)) -> add(N, purge(rm(N, X))) The set Q consists of the following terms: eq(0, 0) eq(0, s(x0)) eq(s(x0), 0) eq(s(x0), s(x1)) rm(x0, nil) rm(x0, add(x1, x2)) ifrm(true, x0, add(x1, x2)) ifrm(false, x0, add(x1, x2)) purge(nil) purge(add(x0, x1)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (5) DependencyGraphProof (EQUIVALENT) The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 3 SCCs with 2 less nodes. ---------------------------------------- (6) Complex Obligation (AND) ---------------------------------------- (7) Obligation: Q DP problem: The TRS P consists of the following rules: EQ(s(X), s(Y)) -> EQ(X, Y) The TRS R consists of the following rules: eq(0, 0) -> true eq(0, s(X)) -> false eq(s(X), 0) -> false eq(s(X), s(Y)) -> eq(X, Y) rm(N, nil) -> nil rm(N, add(M, X)) -> ifrm(eq(N, M), N, add(M, X)) ifrm(true, N, add(M, X)) -> rm(N, X) ifrm(false, N, add(M, X)) -> add(M, rm(N, X)) purge(nil) -> nil purge(add(N, X)) -> add(N, purge(rm(N, X))) The set Q consists of the following terms: eq(0, 0) eq(0, s(x0)) eq(s(x0), 0) eq(s(x0), s(x1)) rm(x0, nil) rm(x0, add(x1, x2)) ifrm(true, x0, add(x1, x2)) ifrm(false, x0, add(x1, x2)) purge(nil) purge(add(x0, x1)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (8) 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. ---------------------------------------- (9) Obligation: Q DP problem: The TRS P consists of the following rules: EQ(s(X), s(Y)) -> EQ(X, Y) R is empty. The set Q consists of the following terms: eq(0, 0) eq(0, s(x0)) eq(s(x0), 0) eq(s(x0), s(x1)) rm(x0, nil) rm(x0, add(x1, x2)) ifrm(true, x0, add(x1, x2)) ifrm(false, x0, add(x1, x2)) purge(nil) purge(add(x0, x1)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (10) 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]. eq(0, 0) eq(0, s(x0)) eq(s(x0), 0) eq(s(x0), s(x1)) rm(x0, nil) rm(x0, add(x1, x2)) ifrm(true, x0, add(x1, x2)) ifrm(false, x0, add(x1, x2)) purge(nil) purge(add(x0, x1)) ---------------------------------------- (11) Obligation: Q DP problem: The TRS P consists of the following rules: EQ(s(X), s(Y)) -> EQ(X, Y) R is empty. Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (12) 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: *EQ(s(X), s(Y)) -> EQ(X, Y) The graph contains the following edges 1 > 1, 2 > 2 ---------------------------------------- (13) YES ---------------------------------------- (14) Obligation: Q DP problem: The TRS P consists of the following rules: RM(N, add(M, X)) -> IFRM(eq(N, M), N, add(M, X)) IFRM(true, N, add(M, X)) -> RM(N, X) IFRM(false, N, add(M, X)) -> RM(N, X) The TRS R consists of the following rules: eq(0, 0) -> true eq(0, s(X)) -> false eq(s(X), 0) -> false eq(s(X), s(Y)) -> eq(X, Y) rm(N, nil) -> nil rm(N, add(M, X)) -> ifrm(eq(N, M), N, add(M, X)) ifrm(true, N, add(M, X)) -> rm(N, X) ifrm(false, N, add(M, X)) -> add(M, rm(N, X)) purge(nil) -> nil purge(add(N, X)) -> add(N, purge(rm(N, X))) The set Q consists of the following terms: eq(0, 0) eq(0, s(x0)) eq(s(x0), 0) eq(s(x0), s(x1)) rm(x0, nil) rm(x0, add(x1, x2)) ifrm(true, x0, add(x1, x2)) ifrm(false, x0, add(x1, x2)) purge(nil) purge(add(x0, x1)) 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: RM(N, add(M, X)) -> IFRM(eq(N, M), N, add(M, X)) IFRM(true, N, add(M, X)) -> RM(N, X) IFRM(false, N, add(M, X)) -> RM(N, X) The TRS R consists of the following rules: eq(0, 0) -> true eq(0, s(X)) -> false eq(s(X), 0) -> false eq(s(X), s(Y)) -> eq(X, Y) The set Q consists of the following terms: eq(0, 0) eq(0, s(x0)) eq(s(x0), 0) eq(s(x0), s(x1)) rm(x0, nil) rm(x0, add(x1, x2)) ifrm(true, x0, add(x1, x2)) ifrm(false, x0, add(x1, x2)) purge(nil) purge(add(x0, x1)) 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]. rm(x0, nil) rm(x0, add(x1, x2)) ifrm(true, x0, add(x1, x2)) ifrm(false, x0, add(x1, x2)) purge(nil) purge(add(x0, x1)) ---------------------------------------- (18) Obligation: Q DP problem: The TRS P consists of the following rules: RM(N, add(M, X)) -> IFRM(eq(N, M), N, add(M, X)) IFRM(true, N, add(M, X)) -> RM(N, X) IFRM(false, N, add(M, X)) -> RM(N, X) The TRS R consists of the following rules: eq(0, 0) -> true eq(0, s(X)) -> false eq(s(X), 0) -> false eq(s(X), s(Y)) -> eq(X, Y) The set Q consists of the following terms: eq(0, 0) eq(0, s(x0)) eq(s(x0), 0) eq(s(x0), s(x1)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (19) 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: *RM(N, add(M, X)) -> IFRM(eq(N, M), N, add(M, X)) The graph contains the following edges 1 >= 2, 2 >= 3 *IFRM(true, N, add(M, X)) -> RM(N, X) The graph contains the following edges 2 >= 1, 3 > 2 *IFRM(false, N, add(M, X)) -> RM(N, X) The graph contains the following edges 2 >= 1, 3 > 2 ---------------------------------------- (20) YES ---------------------------------------- (21) Obligation: Q DP problem: The TRS P consists of the following rules: PURGE(add(N, X)) -> PURGE(rm(N, X)) The TRS R consists of the following rules: eq(0, 0) -> true eq(0, s(X)) -> false eq(s(X), 0) -> false eq(s(X), s(Y)) -> eq(X, Y) rm(N, nil) -> nil rm(N, add(M, X)) -> ifrm(eq(N, M), N, add(M, X)) ifrm(true, N, add(M, X)) -> rm(N, X) ifrm(false, N, add(M, X)) -> add(M, rm(N, X)) purge(nil) -> nil purge(add(N, X)) -> add(N, purge(rm(N, X))) The set Q consists of the following terms: eq(0, 0) eq(0, s(x0)) eq(s(x0), 0) eq(s(x0), s(x1)) rm(x0, nil) rm(x0, add(x1, x2)) ifrm(true, x0, add(x1, x2)) ifrm(false, x0, add(x1, x2)) purge(nil) purge(add(x0, x1)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (22) 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. ---------------------------------------- (23) Obligation: Q DP problem: The TRS P consists of the following rules: PURGE(add(N, X)) -> PURGE(rm(N, X)) The TRS R consists of the following rules: rm(N, nil) -> nil rm(N, add(M, X)) -> ifrm(eq(N, M), N, add(M, X)) ifrm(true, N, add(M, X)) -> rm(N, X) eq(0, 0) -> true eq(0, s(X)) -> false eq(s(X), 0) -> false eq(s(X), s(Y)) -> eq(X, Y) ifrm(false, N, add(M, X)) -> add(M, rm(N, X)) The set Q consists of the following terms: eq(0, 0) eq(0, s(x0)) eq(s(x0), 0) eq(s(x0), s(x1)) rm(x0, nil) rm(x0, add(x1, x2)) ifrm(true, x0, add(x1, x2)) ifrm(false, x0, add(x1, x2)) purge(nil) purge(add(x0, x1)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (24) 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]. purge(nil) purge(add(x0, x1)) ---------------------------------------- (25) Obligation: Q DP problem: The TRS P consists of the following rules: PURGE(add(N, X)) -> PURGE(rm(N, X)) The TRS R consists of the following rules: rm(N, nil) -> nil rm(N, add(M, X)) -> ifrm(eq(N, M), N, add(M, X)) ifrm(true, N, add(M, X)) -> rm(N, X) eq(0, 0) -> true eq(0, s(X)) -> false eq(s(X), 0) -> false eq(s(X), s(Y)) -> eq(X, Y) ifrm(false, N, add(M, X)) -> add(M, rm(N, X)) The set Q consists of the following terms: eq(0, 0) eq(0, s(x0)) eq(s(x0), 0) eq(s(x0), s(x1)) rm(x0, nil) rm(x0, add(x1, x2)) ifrm(true, x0, add(x1, x2)) ifrm(false, x0, add(x1, x2)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (26) QDPOrderProof (EQUIVALENT) We use the reduction pair processor [LPAR04,JAR06]. The following pairs can be oriented strictly and are deleted. PURGE(add(N, X)) -> PURGE(rm(N, X)) The remaining pairs can at least be oriented weakly. Used ordering: Polynomial Order [NEGPOLO,POLO] with Interpretation: POL( PURGE_1(x_1) ) = 2x_1 + 2 POL( rm_2(x_1, x_2) ) = x_2 POL( nil ) = 2 POL( add_2(x_1, x_2) ) = 2x_2 + 2 POL( ifrm_3(x_1, ..., x_3) ) = x_3 POL( eq_2(x_1, x_2) ) = 0 POL( true ) = 2 POL( 0 ) = 0 POL( s_1(x_1) ) = 2x_1 POL( false ) = 0 The following usable rules [FROCOS05] with respect to the argument filtering of the ordering [JAR06] were oriented: rm(N, nil) -> nil rm(N, add(M, X)) -> ifrm(eq(N, M), N, add(M, X)) ifrm(true, N, add(M, X)) -> rm(N, X) ifrm(false, N, add(M, X)) -> add(M, rm(N, X)) ---------------------------------------- (27) Obligation: Q DP problem: P is empty. The TRS R consists of the following rules: rm(N, nil) -> nil rm(N, add(M, X)) -> ifrm(eq(N, M), N, add(M, X)) ifrm(true, N, add(M, X)) -> rm(N, X) eq(0, 0) -> true eq(0, s(X)) -> false eq(s(X), 0) -> false eq(s(X), s(Y)) -> eq(X, Y) ifrm(false, N, add(M, X)) -> add(M, rm(N, X)) The set Q consists of the following terms: eq(0, 0) eq(0, s(x0)) eq(s(x0), 0) eq(s(x0), s(x1)) rm(x0, nil) rm(x0, add(x1, x2)) ifrm(true, x0, add(x1, x2)) ifrm(false, x0, add(x1, x2)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (28) PisEmptyProof (EQUIVALENT) The TRS P is empty. Hence, there is no (P,Q,R) chain. ---------------------------------------- (29) YES