/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# AProVE Commit ID: 48fb2092695e11cc9f56e44b17a92a5f88ffb256 marcel 20180622 unpublished dirty Termination w.r.t. Q of the given QTRS could be proven: (0) QTRS (1) DependencyPairsProof [EQUIVALENT, 0 ms] (2) QDP (3) DependencyGraphProof [EQUIVALENT, 0 ms] (4) AND (5) QDP (6) UsableRulesProof [EQUIVALENT, 0 ms] (7) QDP (8) QDPSizeChangeProof [EQUIVALENT, 0 ms] (9) YES (10) QDP (11) UsableRulesProof [EQUIVALENT, 0 ms] (12) QDP (13) QDPSizeChangeProof [EQUIVALENT, 0 ms] (14) YES (15) QDP (16) QDPOrderProof [EQUIVALENT, 0 ms] (17) QDP (18) PisEmptyProof [EQUIVALENT, 0 ms] (19) YES (20) QDP (21) UsableRulesProof [EQUIVALENT, 0 ms] (22) QDP (23) QDPSizeChangeProof [EQUIVALENT, 0 ms] (24) YES (25) QDP (26) UsableRulesProof [EQUIVALENT, 0 ms] (27) QDP (28) QDPSizeChangeProof [EQUIVALENT, 0 ms] (29) YES (30) QDP (31) UsableRulesProof [EQUIVALENT, 0 ms] (32) QDP (33) MNOCProof [EQUIVALENT, 0 ms] (34) QDP (35) UsableRulesReductionPairsProof [EQUIVALENT, 0 ms] (36) QDP (37) PisEmptyProof [EQUIVALENT, 0 ms] (38) YES (39) QDP (40) UsableRulesProof [EQUIVALENT, 0 ms] (41) QDP (42) UsableRulesReductionPairsProof [EQUIVALENT, 0 ms] (43) QDP (44) MRRProof [EQUIVALENT, 0 ms] (45) QDP (46) MRRProof [EQUIVALENT, 0 ms] (47) QDP (48) DependencyGraphProof [EQUIVALENT, 0 ms] (49) TRUE ---------------------------------------- (0) Obligation: Q restricted rewrite system: The TRS R consists of the following rules: +(0, y) -> y +(s(x), y) -> s(+(x, y)) ++(nil, ys) -> ys ++(:(x, xs), ys) -> :(x, ++(xs, ys)) sum(:(x, nil)) -> :(x, nil) sum(:(x, :(y, xs))) -> sum(:(+(x, y), xs)) sum(++(xs, :(x, :(y, ys)))) -> sum(++(xs, sum(:(x, :(y, ys))))) -(x, 0) -> x -(0, s(y)) -> 0 -(s(x), s(y)) -> -(x, y) quot(0, s(y)) -> 0 quot(s(x), s(y)) -> s(quot(-(x, y), s(y))) length(nil) -> 0 length(:(x, xs)) -> s(length(xs)) hd(:(x, xs)) -> x avg(xs) -> quot(hd(sum(xs)), length(xs)) 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: +^1(s(x), y) -> +^1(x, y) ++^1(:(x, xs), ys) -> ++^1(xs, ys) SUM(:(x, :(y, xs))) -> SUM(:(+(x, y), xs)) SUM(:(x, :(y, xs))) -> +^1(x, y) SUM(++(xs, :(x, :(y, ys)))) -> SUM(++(xs, sum(:(x, :(y, ys))))) SUM(++(xs, :(x, :(y, ys)))) -> ++^1(xs, sum(:(x, :(y, ys)))) SUM(++(xs, :(x, :(y, ys)))) -> SUM(:(x, :(y, ys))) -^1(s(x), s(y)) -> -^1(x, y) QUOT(s(x), s(y)) -> QUOT(-(x, y), s(y)) QUOT(s(x), s(y)) -> -^1(x, y) LENGTH(:(x, xs)) -> LENGTH(xs) AVG(xs) -> QUOT(hd(sum(xs)), length(xs)) AVG(xs) -> HD(sum(xs)) AVG(xs) -> SUM(xs) AVG(xs) -> LENGTH(xs) The TRS R consists of the following rules: +(0, y) -> y +(s(x), y) -> s(+(x, y)) ++(nil, ys) -> ys ++(:(x, xs), ys) -> :(x, ++(xs, ys)) sum(:(x, nil)) -> :(x, nil) sum(:(x, :(y, xs))) -> sum(:(+(x, y), xs)) sum(++(xs, :(x, :(y, ys)))) -> sum(++(xs, sum(:(x, :(y, ys))))) -(x, 0) -> x -(0, s(y)) -> 0 -(s(x), s(y)) -> -(x, y) quot(0, s(y)) -> 0 quot(s(x), s(y)) -> s(quot(-(x, y), s(y))) length(nil) -> 0 length(:(x, xs)) -> s(length(xs)) hd(:(x, xs)) -> x avg(xs) -> quot(hd(sum(xs)), length(xs)) 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 7 SCCs with 8 less nodes. ---------------------------------------- (4) Complex Obligation (AND) ---------------------------------------- (5) Obligation: Q DP problem: The TRS P consists of the following rules: LENGTH(:(x, xs)) -> LENGTH(xs) The TRS R consists of the following rules: +(0, y) -> y +(s(x), y) -> s(+(x, y)) ++(nil, ys) -> ys ++(:(x, xs), ys) -> :(x, ++(xs, ys)) sum(:(x, nil)) -> :(x, nil) sum(:(x, :(y, xs))) -> sum(:(+(x, y), xs)) sum(++(xs, :(x, :(y, ys)))) -> sum(++(xs, sum(:(x, :(y, ys))))) -(x, 0) -> x -(0, s(y)) -> 0 -(s(x), s(y)) -> -(x, y) quot(0, s(y)) -> 0 quot(s(x), s(y)) -> s(quot(-(x, y), s(y))) length(nil) -> 0 length(:(x, xs)) -> s(length(xs)) hd(:(x, xs)) -> x avg(xs) -> quot(hd(sum(xs)), length(xs)) 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: LENGTH(:(x, xs)) -> LENGTH(xs) R is empty. Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (8) 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: *LENGTH(:(x, xs)) -> LENGTH(xs) The graph contains the following edges 1 > 1 ---------------------------------------- (9) YES ---------------------------------------- (10) Obligation: Q DP problem: The TRS P consists of the following rules: -^1(s(x), s(y)) -> -^1(x, y) The TRS R consists of the following rules: +(0, y) -> y +(s(x), y) -> s(+(x, y)) ++(nil, ys) -> ys ++(:(x, xs), ys) -> :(x, ++(xs, ys)) sum(:(x, nil)) -> :(x, nil) sum(:(x, :(y, xs))) -> sum(:(+(x, y), xs)) sum(++(xs, :(x, :(y, ys)))) -> sum(++(xs, sum(:(x, :(y, ys))))) -(x, 0) -> x -(0, s(y)) -> 0 -(s(x), s(y)) -> -(x, y) quot(0, s(y)) -> 0 quot(s(x), s(y)) -> s(quot(-(x, y), s(y))) length(nil) -> 0 length(:(x, xs)) -> s(length(xs)) hd(:(x, xs)) -> x avg(xs) -> quot(hd(sum(xs)), length(xs)) Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (11) 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. ---------------------------------------- (12) Obligation: Q DP problem: The TRS P consists of the following rules: -^1(s(x), s(y)) -> -^1(x, y) R is empty. Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (13) 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: *-^1(s(x), s(y)) -> -^1(x, y) The graph contains the following edges 1 > 1, 2 > 2 ---------------------------------------- (14) YES ---------------------------------------- (15) Obligation: Q DP problem: The TRS P consists of the following rules: QUOT(s(x), s(y)) -> QUOT(-(x, y), s(y)) The TRS R consists of the following rules: +(0, y) -> y +(s(x), y) -> s(+(x, y)) ++(nil, ys) -> ys ++(:(x, xs), ys) -> :(x, ++(xs, ys)) sum(:(x, nil)) -> :(x, nil) sum(:(x, :(y, xs))) -> sum(:(+(x, y), xs)) sum(++(xs, :(x, :(y, ys)))) -> sum(++(xs, sum(:(x, :(y, ys))))) -(x, 0) -> x -(0, s(y)) -> 0 -(s(x), s(y)) -> -(x, y) quot(0, s(y)) -> 0 quot(s(x), s(y)) -> s(quot(-(x, y), s(y))) length(nil) -> 0 length(:(x, xs)) -> s(length(xs)) hd(:(x, xs)) -> x avg(xs) -> quot(hd(sum(xs)), length(xs)) Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (16) QDPOrderProof (EQUIVALENT) We use the reduction pair processor [LPAR04,JAR06]. The following pairs can be oriented strictly and are deleted. QUOT(s(x), s(y)) -> QUOT(-(x, y), s(y)) The remaining pairs can at least be oriented weakly. Used ordering: Combined order from the following AFS and order. QUOT(x1, x2) = x1 s(x1) = s(x1) -(x1, x2) = x1 0 = 0 Knuth-Bendix order [KBO] with precedence:trivial and weight map: s_1=1 0=1 The following usable rules [FROCOS05] with respect to the argument filtering of the ordering [JAR06] were oriented: -(x, 0) -> x -(0, s(y)) -> 0 -(s(x), s(y)) -> -(x, y) ---------------------------------------- (17) Obligation: Q DP problem: P is empty. The TRS R consists of the following rules: +(0, y) -> y +(s(x), y) -> s(+(x, y)) ++(nil, ys) -> ys ++(:(x, xs), ys) -> :(x, ++(xs, ys)) sum(:(x, nil)) -> :(x, nil) sum(:(x, :(y, xs))) -> sum(:(+(x, y), xs)) sum(++(xs, :(x, :(y, ys)))) -> sum(++(xs, sum(:(x, :(y, ys))))) -(x, 0) -> x -(0, s(y)) -> 0 -(s(x), s(y)) -> -(x, y) quot(0, s(y)) -> 0 quot(s(x), s(y)) -> s(quot(-(x, y), s(y))) length(nil) -> 0 length(:(x, xs)) -> s(length(xs)) hd(:(x, xs)) -> x avg(xs) -> quot(hd(sum(xs)), length(xs)) Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (18) PisEmptyProof (EQUIVALENT) The TRS P is empty. Hence, there is no (P,Q,R) chain. ---------------------------------------- (19) YES ---------------------------------------- (20) Obligation: Q DP problem: The TRS P consists of the following rules: ++^1(:(x, xs), ys) -> ++^1(xs, ys) The TRS R consists of the following rules: +(0, y) -> y +(s(x), y) -> s(+(x, y)) ++(nil, ys) -> ys ++(:(x, xs), ys) -> :(x, ++(xs, ys)) sum(:(x, nil)) -> :(x, nil) sum(:(x, :(y, xs))) -> sum(:(+(x, y), xs)) sum(++(xs, :(x, :(y, ys)))) -> sum(++(xs, sum(:(x, :(y, ys))))) -(x, 0) -> x -(0, s(y)) -> 0 -(s(x), s(y)) -> -(x, y) quot(0, s(y)) -> 0 quot(s(x), s(y)) -> s(quot(-(x, y), s(y))) length(nil) -> 0 length(:(x, xs)) -> s(length(xs)) hd(:(x, xs)) -> x avg(xs) -> quot(hd(sum(xs)), length(xs)) Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (21) 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. ---------------------------------------- (22) Obligation: Q DP problem: The TRS P consists of the following rules: ++^1(:(x, xs), ys) -> ++^1(xs, ys) R is empty. Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (23) 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: *++^1(:(x, xs), ys) -> ++^1(xs, ys) The graph contains the following edges 1 > 1, 2 >= 2 ---------------------------------------- (24) YES ---------------------------------------- (25) Obligation: Q DP problem: The TRS P consists of the following rules: +^1(s(x), y) -> +^1(x, y) The TRS R consists of the following rules: +(0, y) -> y +(s(x), y) -> s(+(x, y)) ++(nil, ys) -> ys ++(:(x, xs), ys) -> :(x, ++(xs, ys)) sum(:(x, nil)) -> :(x, nil) sum(:(x, :(y, xs))) -> sum(:(+(x, y), xs)) sum(++(xs, :(x, :(y, ys)))) -> sum(++(xs, sum(:(x, :(y, ys))))) -(x, 0) -> x -(0, s(y)) -> 0 -(s(x), s(y)) -> -(x, y) quot(0, s(y)) -> 0 quot(s(x), s(y)) -> s(quot(-(x, y), s(y))) length(nil) -> 0 length(:(x, xs)) -> s(length(xs)) hd(:(x, xs)) -> x avg(xs) -> quot(hd(sum(xs)), length(xs)) Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (26) 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. ---------------------------------------- (27) Obligation: Q DP problem: The TRS P consists of the following rules: +^1(s(x), y) -> +^1(x, y) R is empty. Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (28) 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: *+^1(s(x), y) -> +^1(x, y) The graph contains the following edges 1 > 1, 2 >= 2 ---------------------------------------- (29) YES ---------------------------------------- (30) Obligation: Q DP problem: The TRS P consists of the following rules: SUM(:(x, :(y, xs))) -> SUM(:(+(x, y), xs)) The TRS R consists of the following rules: +(0, y) -> y +(s(x), y) -> s(+(x, y)) ++(nil, ys) -> ys ++(:(x, xs), ys) -> :(x, ++(xs, ys)) sum(:(x, nil)) -> :(x, nil) sum(:(x, :(y, xs))) -> sum(:(+(x, y), xs)) sum(++(xs, :(x, :(y, ys)))) -> sum(++(xs, sum(:(x, :(y, ys))))) -(x, 0) -> x -(0, s(y)) -> 0 -(s(x), s(y)) -> -(x, y) quot(0, s(y)) -> 0 quot(s(x), s(y)) -> s(quot(-(x, y), s(y))) length(nil) -> 0 length(:(x, xs)) -> s(length(xs)) hd(:(x, xs)) -> x avg(xs) -> quot(hd(sum(xs)), length(xs)) Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (31) 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. ---------------------------------------- (32) Obligation: Q DP problem: The TRS P consists of the following rules: SUM(:(x, :(y, xs))) -> SUM(:(+(x, y), xs)) The TRS R consists of the following rules: +(0, y) -> y +(s(x), y) -> s(+(x, y)) Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (33) MNOCProof (EQUIVALENT) We use the modular non-overlap check [LPAR04] to enlarge Q to all left-hand sides of R. ---------------------------------------- (34) Obligation: Q DP problem: The TRS P consists of the following rules: SUM(:(x, :(y, xs))) -> SUM(:(+(x, y), xs)) The TRS R consists of the following rules: +(0, y) -> y +(s(x), y) -> s(+(x, y)) The set Q consists of the following terms: +(0, x0) +(s(x0), x1) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (35) UsableRulesReductionPairsProof (EQUIVALENT) By using the usable rules with reduction pair processor [LPAR04] with a polynomial ordering [POLO], all dependency pairs and the corresponding usable rules [FROCOS05] can be oriented non-strictly. All non-usable rules are removed, and those dependency pairs and usable rules that have been oriented strictly or contain non-usable symbols in their left-hand side are removed as well. The following dependency pairs can be deleted: SUM(:(x, :(y, xs))) -> SUM(:(+(x, y), xs)) The following rules are removed from R: +(0, y) -> y Used ordering: POLO with Polynomial interpretation [POLO]: POL(+(x_1, x_2)) = x_1 + x_2 POL(0) = 0 POL(:(x_1, x_2)) = 1 + x_1 + 2*x_2 POL(SUM(x_1)) = 2*x_1 POL(s(x_1)) = x_1 ---------------------------------------- (36) Obligation: Q DP problem: P is empty. The TRS R consists of the following rules: +(s(x), y) -> s(+(x, y)) The set Q consists of the following terms: +(0, x0) +(s(x0), x1) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (37) PisEmptyProof (EQUIVALENT) The TRS P is empty. Hence, there is no (P,Q,R) chain. ---------------------------------------- (38) YES ---------------------------------------- (39) Obligation: Q DP problem: The TRS P consists of the following rules: SUM(++(xs, :(x, :(y, ys)))) -> SUM(++(xs, sum(:(x, :(y, ys))))) The TRS R consists of the following rules: +(0, y) -> y +(s(x), y) -> s(+(x, y)) ++(nil, ys) -> ys ++(:(x, xs), ys) -> :(x, ++(xs, ys)) sum(:(x, nil)) -> :(x, nil) sum(:(x, :(y, xs))) -> sum(:(+(x, y), xs)) sum(++(xs, :(x, :(y, ys)))) -> sum(++(xs, sum(:(x, :(y, ys))))) -(x, 0) -> x -(0, s(y)) -> 0 -(s(x), s(y)) -> -(x, y) quot(0, s(y)) -> 0 quot(s(x), s(y)) -> s(quot(-(x, y), s(y))) length(nil) -> 0 length(:(x, xs)) -> s(length(xs)) hd(:(x, xs)) -> x avg(xs) -> quot(hd(sum(xs)), length(xs)) Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (40) 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. ---------------------------------------- (41) Obligation: Q DP problem: The TRS P consists of the following rules: SUM(++(xs, :(x, :(y, ys)))) -> SUM(++(xs, sum(:(x, :(y, ys))))) The TRS R consists of the following rules: sum(:(x, :(y, xs))) -> sum(:(+(x, y), xs)) ++(nil, ys) -> ys ++(:(x, xs), ys) -> :(x, ++(xs, ys)) +(0, y) -> y +(s(x), y) -> s(+(x, y)) sum(:(x, nil)) -> :(x, nil) Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (42) UsableRulesReductionPairsProof (EQUIVALENT) By using the usable rules with reduction pair processor [LPAR04] with a polynomial ordering [POLO], all dependency pairs and the corresponding usable rules [FROCOS05] can be oriented non-strictly. All non-usable rules are removed, and those dependency pairs and usable rules that have been oriented strictly or contain non-usable symbols in their left-hand side are removed as well. No dependency pairs are removed. The following rules are removed from R: +(0, y) -> y Used ordering: POLO with Polynomial interpretation [POLO]: POL(+(x_1, x_2)) = x_1 + x_2 POL(++(x_1, x_2)) = 2*x_1 + x_2 POL(0) = 0 POL(:(x_1, x_2)) = x_1 + x_2 POL(SUM(x_1)) = x_1 POL(nil) = 0 POL(s(x_1)) = x_1 POL(sum(x_1)) = x_1 ---------------------------------------- (43) Obligation: Q DP problem: The TRS P consists of the following rules: SUM(++(xs, :(x, :(y, ys)))) -> SUM(++(xs, sum(:(x, :(y, ys))))) The TRS R consists of the following rules: sum(:(x, :(y, xs))) -> sum(:(+(x, y), xs)) ++(nil, ys) -> ys ++(:(x, xs), ys) -> :(x, ++(xs, ys)) +(s(x), y) -> s(+(x, y)) sum(:(x, nil)) -> :(x, nil) Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (44) MRRProof (EQUIVALENT) By using the rule removal processor [LPAR04] with the following ordering, at least one Dependency Pair or term rewrite system rule of this QDP problem can be strictly oriented. Strictly oriented rules of the TRS R: ++(nil, ys) -> ys Used ordering: Polynomial interpretation [POLO]: POL(+(x_1, x_2)) = x_1 + x_2 POL(++(x_1, x_2)) = 2*x_1 + x_2 POL(:(x_1, x_2)) = x_1 + x_2 POL(SUM(x_1)) = 2*x_1 POL(nil) = 2 POL(s(x_1)) = x_1 POL(sum(x_1)) = x_1 ---------------------------------------- (45) Obligation: Q DP problem: The TRS P consists of the following rules: SUM(++(xs, :(x, :(y, ys)))) -> SUM(++(xs, sum(:(x, :(y, ys))))) The TRS R consists of the following rules: sum(:(x, :(y, xs))) -> sum(:(+(x, y), xs)) ++(:(x, xs), ys) -> :(x, ++(xs, ys)) +(s(x), y) -> s(+(x, y)) sum(:(x, nil)) -> :(x, nil) Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (46) MRRProof (EQUIVALENT) By using the rule removal processor [LPAR04] with the following ordering, at least one Dependency Pair or term rewrite system rule of this QDP problem can be strictly oriented. Strictly oriented rules of the TRS R: sum(:(x, :(y, xs))) -> sum(:(+(x, y), xs)) ++(:(x, xs), ys) -> :(x, ++(xs, ys)) Used ordering: Polynomial interpretation [POLO]: POL(+(x_1, x_2)) = x_1 + x_2 POL(++(x_1, x_2)) = 2*x_1 + x_2 POL(:(x_1, x_2)) = 2 + x_1 + x_2 POL(SUM(x_1)) = 2*x_1 POL(nil) = 0 POL(s(x_1)) = x_1 POL(sum(x_1)) = x_1 ---------------------------------------- (47) Obligation: Q DP problem: The TRS P consists of the following rules: SUM(++(xs, :(x, :(y, ys)))) -> SUM(++(xs, sum(:(x, :(y, ys))))) The TRS R consists of the following rules: +(s(x), y) -> s(+(x, y)) sum(:(x, nil)) -> :(x, nil) Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (48) DependencyGraphProof (EQUIVALENT) The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 0 SCCs with 1 less node. ---------------------------------------- (49) TRUE