/export/starexec/sandbox2/solver/bin/starexec_run_standard /export/starexec/sandbox2/benchmark/theBenchmark.xml /export/starexec/sandbox2/output/output_files -------------------------------------------------------------------------------- YES proof of /export/starexec/sandbox2/benchmark/theBenchmark.xml # AProVE Commit ID: 48fb2092695e11cc9f56e44b17a92a5f88ffb256 marcel 20180622 unpublished dirty Termination w.r.t. Q of the given QTRS could be proven: (0) QTRS (1) Overlay + Local Confluence [EQUIVALENT, 21 ms] (2) QTRS (3) DependencyPairsProof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, 0 ms] (11) QDP (12) QDPSizeChangeProof [EQUIVALENT, 0 ms] (13) YES (14) QDP (15) UsableRulesProof [EQUIVALENT, 0 ms] (16) QDP (17) QReductionProof [EQUIVALENT, 0 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) QDPSizeChangeProof [EQUIVALENT, 0 ms] (27) YES (28) QDP (29) UsableRulesProof [EQUIVALENT, 0 ms] (30) QDP (31) QReductionProof [EQUIVALENT, 0 ms] (32) QDP (33) QDPOrderProof [EQUIVALENT, 35 ms] (34) QDP (35) DependencyGraphProof [EQUIVALENT, 0 ms] (36) TRUE ---------------------------------------- (0) Obligation: Q restricted rewrite system: The TRS R consists of the following rules: lt(0, s(X)) -> true lt(s(X), 0) -> false lt(s(X), s(Y)) -> lt(X, Y) append(nil, Y) -> Y append(add(N, X), Y) -> add(N, append(X, Y)) split(N, nil) -> pair(nil, nil) split(N, add(M, Y)) -> f_1(split(N, Y), N, M, Y) f_1(pair(X, Z), N, M, Y) -> f_2(lt(N, M), N, M, Y, X, Z) f_2(true, N, M, Y, X, Z) -> pair(X, add(M, Z)) f_2(false, N, M, Y, X, Z) -> pair(add(M, X), Z) qsort(nil) -> nil qsort(add(N, X)) -> f_3(split(N, X), N, X) f_3(pair(Y, Z), N, X) -> append(qsort(Y), add(X, qsort(Z))) 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: lt(0, s(X)) -> true lt(s(X), 0) -> false lt(s(X), s(Y)) -> lt(X, Y) append(nil, Y) -> Y append(add(N, X), Y) -> add(N, append(X, Y)) split(N, nil) -> pair(nil, nil) split(N, add(M, Y)) -> f_1(split(N, Y), N, M, Y) f_1(pair(X, Z), N, M, Y) -> f_2(lt(N, M), N, M, Y, X, Z) f_2(true, N, M, Y, X, Z) -> pair(X, add(M, Z)) f_2(false, N, M, Y, X, Z) -> pair(add(M, X), Z) qsort(nil) -> nil qsort(add(N, X)) -> f_3(split(N, X), N, X) f_3(pair(Y, Z), N, X) -> append(qsort(Y), add(X, qsort(Z))) The set Q consists of the following terms: lt(0, s(x0)) lt(s(x0), 0) lt(s(x0), s(x1)) append(nil, x0) append(add(x0, x1), x2) split(x0, nil) split(x0, add(x1, x2)) f_1(pair(x0, x1), x2, x3, x4) f_2(true, x0, x1, x2, x3, x4) f_2(false, x0, x1, x2, x3, x4) qsort(nil) qsort(add(x0, x1)) f_3(pair(x0, x1), x2, x3) ---------------------------------------- (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: LT(s(X), s(Y)) -> LT(X, Y) APPEND(add(N, X), Y) -> APPEND(X, Y) SPLIT(N, add(M, Y)) -> F_1(split(N, Y), N, M, Y) SPLIT(N, add(M, Y)) -> SPLIT(N, Y) F_1(pair(X, Z), N, M, Y) -> F_2(lt(N, M), N, M, Y, X, Z) F_1(pair(X, Z), N, M, Y) -> LT(N, M) QSORT(add(N, X)) -> F_3(split(N, X), N, X) QSORT(add(N, X)) -> SPLIT(N, X) F_3(pair(Y, Z), N, X) -> APPEND(qsort(Y), add(X, qsort(Z))) F_3(pair(Y, Z), N, X) -> QSORT(Y) F_3(pair(Y, Z), N, X) -> QSORT(Z) The TRS R consists of the following rules: lt(0, s(X)) -> true lt(s(X), 0) -> false lt(s(X), s(Y)) -> lt(X, Y) append(nil, Y) -> Y append(add(N, X), Y) -> add(N, append(X, Y)) split(N, nil) -> pair(nil, nil) split(N, add(M, Y)) -> f_1(split(N, Y), N, M, Y) f_1(pair(X, Z), N, M, Y) -> f_2(lt(N, M), N, M, Y, X, Z) f_2(true, N, M, Y, X, Z) -> pair(X, add(M, Z)) f_2(false, N, M, Y, X, Z) -> pair(add(M, X), Z) qsort(nil) -> nil qsort(add(N, X)) -> f_3(split(N, X), N, X) f_3(pair(Y, Z), N, X) -> append(qsort(Y), add(X, qsort(Z))) The set Q consists of the following terms: lt(0, s(x0)) lt(s(x0), 0) lt(s(x0), s(x1)) append(nil, x0) append(add(x0, x1), x2) split(x0, nil) split(x0, add(x1, x2)) f_1(pair(x0, x1), x2, x3, x4) f_2(true, x0, x1, x2, x3, x4) f_2(false, x0, x1, x2, x3, x4) qsort(nil) qsort(add(x0, x1)) f_3(pair(x0, x1), x2, x3) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (5) DependencyGraphProof (EQUIVALENT) The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 4 SCCs with 5 less nodes. ---------------------------------------- (6) Complex Obligation (AND) ---------------------------------------- (7) Obligation: Q DP problem: The TRS P consists of the following rules: APPEND(add(N, X), Y) -> APPEND(X, Y) The TRS R consists of the following rules: lt(0, s(X)) -> true lt(s(X), 0) -> false lt(s(X), s(Y)) -> lt(X, Y) append(nil, Y) -> Y append(add(N, X), Y) -> add(N, append(X, Y)) split(N, nil) -> pair(nil, nil) split(N, add(M, Y)) -> f_1(split(N, Y), N, M, Y) f_1(pair(X, Z), N, M, Y) -> f_2(lt(N, M), N, M, Y, X, Z) f_2(true, N, M, Y, X, Z) -> pair(X, add(M, Z)) f_2(false, N, M, Y, X, Z) -> pair(add(M, X), Z) qsort(nil) -> nil qsort(add(N, X)) -> f_3(split(N, X), N, X) f_3(pair(Y, Z), N, X) -> append(qsort(Y), add(X, qsort(Z))) The set Q consists of the following terms: lt(0, s(x0)) lt(s(x0), 0) lt(s(x0), s(x1)) append(nil, x0) append(add(x0, x1), x2) split(x0, nil) split(x0, add(x1, x2)) f_1(pair(x0, x1), x2, x3, x4) f_2(true, x0, x1, x2, x3, x4) f_2(false, x0, x1, x2, x3, x4) qsort(nil) qsort(add(x0, x1)) f_3(pair(x0, x1), x2, x3) 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: APPEND(add(N, X), Y) -> APPEND(X, Y) R is empty. The set Q consists of the following terms: lt(0, s(x0)) lt(s(x0), 0) lt(s(x0), s(x1)) append(nil, x0) append(add(x0, x1), x2) split(x0, nil) split(x0, add(x1, x2)) f_1(pair(x0, x1), x2, x3, x4) f_2(true, x0, x1, x2, x3, x4) f_2(false, x0, x1, x2, x3, x4) qsort(nil) qsort(add(x0, x1)) f_3(pair(x0, x1), x2, x3) 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]. lt(0, s(x0)) lt(s(x0), 0) lt(s(x0), s(x1)) append(nil, x0) append(add(x0, x1), x2) split(x0, nil) split(x0, add(x1, x2)) f_1(pair(x0, x1), x2, x3, x4) f_2(true, x0, x1, x2, x3, x4) f_2(false, x0, x1, x2, x3, x4) qsort(nil) qsort(add(x0, x1)) f_3(pair(x0, x1), x2, x3) ---------------------------------------- (11) Obligation: Q DP problem: The TRS P consists of the following rules: APPEND(add(N, X), Y) -> APPEND(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: *APPEND(add(N, X), Y) -> APPEND(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: LT(s(X), s(Y)) -> LT(X, Y) The TRS R consists of the following rules: lt(0, s(X)) -> true lt(s(X), 0) -> false lt(s(X), s(Y)) -> lt(X, Y) append(nil, Y) -> Y append(add(N, X), Y) -> add(N, append(X, Y)) split(N, nil) -> pair(nil, nil) split(N, add(M, Y)) -> f_1(split(N, Y), N, M, Y) f_1(pair(X, Z), N, M, Y) -> f_2(lt(N, M), N, M, Y, X, Z) f_2(true, N, M, Y, X, Z) -> pair(X, add(M, Z)) f_2(false, N, M, Y, X, Z) -> pair(add(M, X), Z) qsort(nil) -> nil qsort(add(N, X)) -> f_3(split(N, X), N, X) f_3(pair(Y, Z), N, X) -> append(qsort(Y), add(X, qsort(Z))) The set Q consists of the following terms: lt(0, s(x0)) lt(s(x0), 0) lt(s(x0), s(x1)) append(nil, x0) append(add(x0, x1), x2) split(x0, nil) split(x0, add(x1, x2)) f_1(pair(x0, x1), x2, x3, x4) f_2(true, x0, x1, x2, x3, x4) f_2(false, x0, x1, x2, x3, x4) qsort(nil) qsort(add(x0, x1)) f_3(pair(x0, x1), x2, x3) 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: LT(s(X), s(Y)) -> LT(X, Y) R is empty. The set Q consists of the following terms: lt(0, s(x0)) lt(s(x0), 0) lt(s(x0), s(x1)) append(nil, x0) append(add(x0, x1), x2) split(x0, nil) split(x0, add(x1, x2)) f_1(pair(x0, x1), x2, x3, x4) f_2(true, x0, x1, x2, x3, x4) f_2(false, x0, x1, x2, x3, x4) qsort(nil) qsort(add(x0, x1)) f_3(pair(x0, x1), x2, x3) 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]. lt(0, s(x0)) lt(s(x0), 0) lt(s(x0), s(x1)) append(nil, x0) append(add(x0, x1), x2) split(x0, nil) split(x0, add(x1, x2)) f_1(pair(x0, x1), x2, x3, x4) f_2(true, x0, x1, x2, x3, x4) f_2(false, x0, x1, x2, x3, x4) qsort(nil) qsort(add(x0, x1)) f_3(pair(x0, x1), x2, x3) ---------------------------------------- (18) Obligation: Q DP problem: The TRS P consists of the following rules: LT(s(X), s(Y)) -> LT(X, Y) R is empty. Q is empty. 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: *LT(s(X), s(Y)) -> LT(X, Y) The graph contains the following edges 1 > 1, 2 > 2 ---------------------------------------- (20) YES ---------------------------------------- (21) Obligation: Q DP problem: The TRS P consists of the following rules: SPLIT(N, add(M, Y)) -> SPLIT(N, Y) The TRS R consists of the following rules: lt(0, s(X)) -> true lt(s(X), 0) -> false lt(s(X), s(Y)) -> lt(X, Y) append(nil, Y) -> Y append(add(N, X), Y) -> add(N, append(X, Y)) split(N, nil) -> pair(nil, nil) split(N, add(M, Y)) -> f_1(split(N, Y), N, M, Y) f_1(pair(X, Z), N, M, Y) -> f_2(lt(N, M), N, M, Y, X, Z) f_2(true, N, M, Y, X, Z) -> pair(X, add(M, Z)) f_2(false, N, M, Y, X, Z) -> pair(add(M, X), Z) qsort(nil) -> nil qsort(add(N, X)) -> f_3(split(N, X), N, X) f_3(pair(Y, Z), N, X) -> append(qsort(Y), add(X, qsort(Z))) The set Q consists of the following terms: lt(0, s(x0)) lt(s(x0), 0) lt(s(x0), s(x1)) append(nil, x0) append(add(x0, x1), x2) split(x0, nil) split(x0, add(x1, x2)) f_1(pair(x0, x1), x2, x3, x4) f_2(true, x0, x1, x2, x3, x4) f_2(false, x0, x1, x2, x3, x4) qsort(nil) qsort(add(x0, x1)) f_3(pair(x0, x1), x2, x3) 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: SPLIT(N, add(M, Y)) -> SPLIT(N, Y) R is empty. The set Q consists of the following terms: lt(0, s(x0)) lt(s(x0), 0) lt(s(x0), s(x1)) append(nil, x0) append(add(x0, x1), x2) split(x0, nil) split(x0, add(x1, x2)) f_1(pair(x0, x1), x2, x3, x4) f_2(true, x0, x1, x2, x3, x4) f_2(false, x0, x1, x2, x3, x4) qsort(nil) qsort(add(x0, x1)) f_3(pair(x0, x1), x2, x3) 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]. lt(0, s(x0)) lt(s(x0), 0) lt(s(x0), s(x1)) append(nil, x0) append(add(x0, x1), x2) split(x0, nil) split(x0, add(x1, x2)) f_1(pair(x0, x1), x2, x3, x4) f_2(true, x0, x1, x2, x3, x4) f_2(false, x0, x1, x2, x3, x4) qsort(nil) qsort(add(x0, x1)) f_3(pair(x0, x1), x2, x3) ---------------------------------------- (25) Obligation: Q DP problem: The TRS P consists of the following rules: SPLIT(N, add(M, Y)) -> SPLIT(N, Y) R is empty. Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (26) 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: *SPLIT(N, add(M, Y)) -> SPLIT(N, Y) The graph contains the following edges 1 >= 1, 2 > 2 ---------------------------------------- (27) YES ---------------------------------------- (28) Obligation: Q DP problem: The TRS P consists of the following rules: QSORT(add(N, X)) -> F_3(split(N, X), N, X) F_3(pair(Y, Z), N, X) -> QSORT(Y) F_3(pair(Y, Z), N, X) -> QSORT(Z) The TRS R consists of the following rules: lt(0, s(X)) -> true lt(s(X), 0) -> false lt(s(X), s(Y)) -> lt(X, Y) append(nil, Y) -> Y append(add(N, X), Y) -> add(N, append(X, Y)) split(N, nil) -> pair(nil, nil) split(N, add(M, Y)) -> f_1(split(N, Y), N, M, Y) f_1(pair(X, Z), N, M, Y) -> f_2(lt(N, M), N, M, Y, X, Z) f_2(true, N, M, Y, X, Z) -> pair(X, add(M, Z)) f_2(false, N, M, Y, X, Z) -> pair(add(M, X), Z) qsort(nil) -> nil qsort(add(N, X)) -> f_3(split(N, X), N, X) f_3(pair(Y, Z), N, X) -> append(qsort(Y), add(X, qsort(Z))) The set Q consists of the following terms: lt(0, s(x0)) lt(s(x0), 0) lt(s(x0), s(x1)) append(nil, x0) append(add(x0, x1), x2) split(x0, nil) split(x0, add(x1, x2)) f_1(pair(x0, x1), x2, x3, x4) f_2(true, x0, x1, x2, x3, x4) f_2(false, x0, x1, x2, x3, x4) qsort(nil) qsort(add(x0, x1)) f_3(pair(x0, x1), x2, x3) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (29) 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. ---------------------------------------- (30) Obligation: Q DP problem: The TRS P consists of the following rules: QSORT(add(N, X)) -> F_3(split(N, X), N, X) F_3(pair(Y, Z), N, X) -> QSORT(Y) F_3(pair(Y, Z), N, X) -> QSORT(Z) The TRS R consists of the following rules: split(N, nil) -> pair(nil, nil) split(N, add(M, Y)) -> f_1(split(N, Y), N, M, Y) f_1(pair(X, Z), N, M, Y) -> f_2(lt(N, M), N, M, Y, X, Z) lt(0, s(X)) -> true lt(s(X), 0) -> false lt(s(X), s(Y)) -> lt(X, Y) f_2(true, N, M, Y, X, Z) -> pair(X, add(M, Z)) f_2(false, N, M, Y, X, Z) -> pair(add(M, X), Z) The set Q consists of the following terms: lt(0, s(x0)) lt(s(x0), 0) lt(s(x0), s(x1)) append(nil, x0) append(add(x0, x1), x2) split(x0, nil) split(x0, add(x1, x2)) f_1(pair(x0, x1), x2, x3, x4) f_2(true, x0, x1, x2, x3, x4) f_2(false, x0, x1, x2, x3, x4) qsort(nil) qsort(add(x0, x1)) f_3(pair(x0, x1), x2, x3) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (31) 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]. append(nil, x0) append(add(x0, x1), x2) qsort(nil) qsort(add(x0, x1)) f_3(pair(x0, x1), x2, x3) ---------------------------------------- (32) Obligation: Q DP problem: The TRS P consists of the following rules: QSORT(add(N, X)) -> F_3(split(N, X), N, X) F_3(pair(Y, Z), N, X) -> QSORT(Y) F_3(pair(Y, Z), N, X) -> QSORT(Z) The TRS R consists of the following rules: split(N, nil) -> pair(nil, nil) split(N, add(M, Y)) -> f_1(split(N, Y), N, M, Y) f_1(pair(X, Z), N, M, Y) -> f_2(lt(N, M), N, M, Y, X, Z) lt(0, s(X)) -> true lt(s(X), 0) -> false lt(s(X), s(Y)) -> lt(X, Y) f_2(true, N, M, Y, X, Z) -> pair(X, add(M, Z)) f_2(false, N, M, Y, X, Z) -> pair(add(M, X), Z) The set Q consists of the following terms: lt(0, s(x0)) lt(s(x0), 0) lt(s(x0), s(x1)) split(x0, nil) split(x0, add(x1, x2)) f_1(pair(x0, x1), x2, x3, x4) f_2(true, x0, x1, x2, x3, x4) f_2(false, x0, x1, x2, x3, x4) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (33) QDPOrderProof (EQUIVALENT) We use the reduction pair processor [LPAR04,JAR06]. The following pairs can be oriented strictly and are deleted. QSORT(add(N, X)) -> F_3(split(N, X), N, X) The remaining pairs can at least be oriented weakly. Used ordering: Polynomial Order [NEGPOLO,POLO] with Interpretation: POL( F_3_3(x_1, ..., x_3) ) = 2x_1 + 2 POL( split_2(x_1, x_2) ) = x_2 POL( nil ) = 0 POL( pair_2(x_1, x_2) ) = max{0, x_1 + x_2 - 1} POL( add_2(x_1, x_2) ) = x_2 + 2 POL( f_1_4(x_1, ..., x_4) ) = x_1 + 2 POL( f_2_6(x_1, ..., x_6) ) = x_1 + x_5 + x_6 POL( lt_2(x_1, x_2) ) = 1 POL( 0 ) = 0 POL( s_1(x_1) ) = 2x_1 POL( true ) = 1 POL( false ) = 1 POL( QSORT_1(x_1) ) = 2x_1 The following usable rules [FROCOS05] with respect to the argument filtering of the ordering [JAR06] were oriented: split(N, nil) -> pair(nil, nil) split(N, add(M, Y)) -> f_1(split(N, Y), N, M, Y) f_1(pair(X, Z), N, M, Y) -> f_2(lt(N, M), N, M, Y, X, Z) lt(0, s(X)) -> true lt(s(X), 0) -> false lt(s(X), s(Y)) -> lt(X, Y) f_2(true, N, M, Y, X, Z) -> pair(X, add(M, Z)) f_2(false, N, M, Y, X, Z) -> pair(add(M, X), Z) ---------------------------------------- (34) Obligation: Q DP problem: The TRS P consists of the following rules: F_3(pair(Y, Z), N, X) -> QSORT(Y) F_3(pair(Y, Z), N, X) -> QSORT(Z) The TRS R consists of the following rules: split(N, nil) -> pair(nil, nil) split(N, add(M, Y)) -> f_1(split(N, Y), N, M, Y) f_1(pair(X, Z), N, M, Y) -> f_2(lt(N, M), N, M, Y, X, Z) lt(0, s(X)) -> true lt(s(X), 0) -> false lt(s(X), s(Y)) -> lt(X, Y) f_2(true, N, M, Y, X, Z) -> pair(X, add(M, Z)) f_2(false, N, M, Y, X, Z) -> pair(add(M, X), Z) The set Q consists of the following terms: lt(0, s(x0)) lt(s(x0), 0) lt(s(x0), s(x1)) split(x0, nil) split(x0, add(x1, x2)) f_1(pair(x0, x1), x2, x3, x4) f_2(true, x0, x1, x2, x3, x4) f_2(false, x0, x1, x2, x3, x4) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (35) DependencyGraphProof (EQUIVALENT) The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 0 SCCs with 2 less nodes. ---------------------------------------- (36) TRUE