/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# AProVE Commit ID: c69e44bd14796315568835c1ffa2502984884775 mhark 20210624 unpublished Termination w.r.t. Q of the given QTRS could be proven: (0) QTRS (1) Overlay + Local Confluence [EQUIVALENT, 2 ms] (2) QTRS (3) DependencyPairsProof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, 2 ms] (18) QDP (19) QDPOrderProof [EQUIVALENT, 17 ms] (20) QDP (21) DependencyGraphProof [EQUIVALENT, 0 ms] (22) TRUE (23) QDP (24) UsableRulesProof [EQUIVALENT, 0 ms] (25) QDP (26) QReductionProof [EQUIVALENT, 0 ms] (27) QDP (28) QDPSizeChangeProof [EQUIVALENT, 0 ms] (29) YES (30) QDP (31) UsableRulesProof [EQUIVALENT, 0 ms] (32) QDP (33) QReductionProof [EQUIVALENT, 0 ms] (34) QDP (35) QDPSizeChangeProof [EQUIVALENT, 0 ms] (36) YES (37) QDP (38) UsableRulesProof [EQUIVALENT, 0 ms] (39) QDP (40) QReductionProof [EQUIVALENT, 1 ms] (41) QDP (42) QDPOrderProof [EQUIVALENT, 205 ms] (43) QDP (44) PisEmptyProof [EQUIVALENT, 0 ms] (45) YES ---------------------------------------- (0) Obligation: Q restricted rewrite system: The TRS R consists of the following rules: eq(0, 0) -> true eq(0, s(m)) -> false eq(s(n), 0) -> false eq(s(n), s(m)) -> eq(n, m) le(0, m) -> true le(s(n), 0) -> false le(s(n), s(m)) -> le(n, m) min(cons(x, nil)) -> x min(cons(n, cons(m, x))) -> if_min(le(n, m), cons(n, cons(m, x))) if_min(true, cons(n, cons(m, x))) -> min(cons(n, x)) if_min(false, cons(n, cons(m, x))) -> min(cons(m, x)) replace(n, m, nil) -> nil replace(n, m, cons(k, x)) -> if_replace(eq(n, k), n, m, cons(k, x)) if_replace(true, n, m, cons(k, x)) -> cons(m, x) if_replace(false, n, m, cons(k, x)) -> cons(k, replace(n, m, x)) empty(nil) -> true empty(cons(n, x)) -> false head(cons(n, x)) -> n tail(nil) -> nil tail(cons(n, x)) -> x sort(x) -> sortIter(x, nil) sortIter(x, y) -> if(empty(x), x, y, append(y, cons(min(x), nil))) if(true, x, y, z) -> y if(false, x, y, z) -> sortIter(replace(min(x), head(x), tail(x)), 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: eq(0, 0) -> true eq(0, s(m)) -> false eq(s(n), 0) -> false eq(s(n), s(m)) -> eq(n, m) le(0, m) -> true le(s(n), 0) -> false le(s(n), s(m)) -> le(n, m) min(cons(x, nil)) -> x min(cons(n, cons(m, x))) -> if_min(le(n, m), cons(n, cons(m, x))) if_min(true, cons(n, cons(m, x))) -> min(cons(n, x)) if_min(false, cons(n, cons(m, x))) -> min(cons(m, x)) replace(n, m, nil) -> nil replace(n, m, cons(k, x)) -> if_replace(eq(n, k), n, m, cons(k, x)) if_replace(true, n, m, cons(k, x)) -> cons(m, x) if_replace(false, n, m, cons(k, x)) -> cons(k, replace(n, m, x)) empty(nil) -> true empty(cons(n, x)) -> false head(cons(n, x)) -> n tail(nil) -> nil tail(cons(n, x)) -> x sort(x) -> sortIter(x, nil) sortIter(x, y) -> if(empty(x), x, y, append(y, cons(min(x), nil))) if(true, x, y, z) -> y if(false, x, y, z) -> sortIter(replace(min(x), head(x), tail(x)), z) The set Q consists of the following terms: eq(0, 0) eq(0, s(x0)) eq(s(x0), 0) eq(s(x0), s(x1)) le(0, x0) le(s(x0), 0) le(s(x0), s(x1)) min(cons(x0, nil)) min(cons(x0, cons(x1, x2))) if_min(true, cons(x0, cons(x1, x2))) if_min(false, cons(x0, cons(x1, x2))) replace(x0, x1, nil) replace(x0, x1, cons(x2, x3)) if_replace(true, x0, x1, cons(x2, x3)) if_replace(false, x0, x1, cons(x2, x3)) empty(nil) empty(cons(x0, x1)) head(cons(x0, x1)) tail(nil) tail(cons(x0, x1)) sort(x0) sortIter(x0, x1) if(true, x0, x1, x2) if(false, x0, x1, x2) ---------------------------------------- (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(n), s(m)) -> EQ(n, m) LE(s(n), s(m)) -> LE(n, m) MIN(cons(n, cons(m, x))) -> IF_MIN(le(n, m), cons(n, cons(m, x))) MIN(cons(n, cons(m, x))) -> LE(n, m) IF_MIN(true, cons(n, cons(m, x))) -> MIN(cons(n, x)) IF_MIN(false, cons(n, cons(m, x))) -> MIN(cons(m, x)) REPLACE(n, m, cons(k, x)) -> IF_REPLACE(eq(n, k), n, m, cons(k, x)) REPLACE(n, m, cons(k, x)) -> EQ(n, k) IF_REPLACE(false, n, m, cons(k, x)) -> REPLACE(n, m, x) SORT(x) -> SORTITER(x, nil) SORTITER(x, y) -> IF(empty(x), x, y, append(y, cons(min(x), nil))) SORTITER(x, y) -> EMPTY(x) SORTITER(x, y) -> MIN(x) IF(false, x, y, z) -> SORTITER(replace(min(x), head(x), tail(x)), z) IF(false, x, y, z) -> REPLACE(min(x), head(x), tail(x)) IF(false, x, y, z) -> MIN(x) IF(false, x, y, z) -> HEAD(x) IF(false, x, y, z) -> TAIL(x) The TRS R consists of the following rules: eq(0, 0) -> true eq(0, s(m)) -> false eq(s(n), 0) -> false eq(s(n), s(m)) -> eq(n, m) le(0, m) -> true le(s(n), 0) -> false le(s(n), s(m)) -> le(n, m) min(cons(x, nil)) -> x min(cons(n, cons(m, x))) -> if_min(le(n, m), cons(n, cons(m, x))) if_min(true, cons(n, cons(m, x))) -> min(cons(n, x)) if_min(false, cons(n, cons(m, x))) -> min(cons(m, x)) replace(n, m, nil) -> nil replace(n, m, cons(k, x)) -> if_replace(eq(n, k), n, m, cons(k, x)) if_replace(true, n, m, cons(k, x)) -> cons(m, x) if_replace(false, n, m, cons(k, x)) -> cons(k, replace(n, m, x)) empty(nil) -> true empty(cons(n, x)) -> false head(cons(n, x)) -> n tail(nil) -> nil tail(cons(n, x)) -> x sort(x) -> sortIter(x, nil) sortIter(x, y) -> if(empty(x), x, y, append(y, cons(min(x), nil))) if(true, x, y, z) -> y if(false, x, y, z) -> sortIter(replace(min(x), head(x), tail(x)), z) The set Q consists of the following terms: eq(0, 0) eq(0, s(x0)) eq(s(x0), 0) eq(s(x0), s(x1)) le(0, x0) le(s(x0), 0) le(s(x0), s(x1)) min(cons(x0, nil)) min(cons(x0, cons(x1, x2))) if_min(true, cons(x0, cons(x1, x2))) if_min(false, cons(x0, cons(x1, x2))) replace(x0, x1, nil) replace(x0, x1, cons(x2, x3)) if_replace(true, x0, x1, cons(x2, x3)) if_replace(false, x0, x1, cons(x2, x3)) empty(nil) empty(cons(x0, x1)) head(cons(x0, x1)) tail(nil) tail(cons(x0, x1)) sort(x0) sortIter(x0, x1) if(true, x0, x1, x2) if(false, x0, x1, x2) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (5) DependencyGraphProof (EQUIVALENT) The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 5 SCCs with 9 less nodes. ---------------------------------------- (6) Complex Obligation (AND) ---------------------------------------- (7) Obligation: Q DP problem: The TRS P consists of the following rules: LE(s(n), s(m)) -> LE(n, m) The TRS R consists of the following rules: eq(0, 0) -> true eq(0, s(m)) -> false eq(s(n), 0) -> false eq(s(n), s(m)) -> eq(n, m) le(0, m) -> true le(s(n), 0) -> false le(s(n), s(m)) -> le(n, m) min(cons(x, nil)) -> x min(cons(n, cons(m, x))) -> if_min(le(n, m), cons(n, cons(m, x))) if_min(true, cons(n, cons(m, x))) -> min(cons(n, x)) if_min(false, cons(n, cons(m, x))) -> min(cons(m, x)) replace(n, m, nil) -> nil replace(n, m, cons(k, x)) -> if_replace(eq(n, k), n, m, cons(k, x)) if_replace(true, n, m, cons(k, x)) -> cons(m, x) if_replace(false, n, m, cons(k, x)) -> cons(k, replace(n, m, x)) empty(nil) -> true empty(cons(n, x)) -> false head(cons(n, x)) -> n tail(nil) -> nil tail(cons(n, x)) -> x sort(x) -> sortIter(x, nil) sortIter(x, y) -> if(empty(x), x, y, append(y, cons(min(x), nil))) if(true, x, y, z) -> y if(false, x, y, z) -> sortIter(replace(min(x), head(x), tail(x)), z) The set Q consists of the following terms: eq(0, 0) eq(0, s(x0)) eq(s(x0), 0) eq(s(x0), s(x1)) le(0, x0) le(s(x0), 0) le(s(x0), s(x1)) min(cons(x0, nil)) min(cons(x0, cons(x1, x2))) if_min(true, cons(x0, cons(x1, x2))) if_min(false, cons(x0, cons(x1, x2))) replace(x0, x1, nil) replace(x0, x1, cons(x2, x3)) if_replace(true, x0, x1, cons(x2, x3)) if_replace(false, x0, x1, cons(x2, x3)) empty(nil) empty(cons(x0, x1)) head(cons(x0, x1)) tail(nil) tail(cons(x0, x1)) sort(x0) sortIter(x0, x1) if(true, x0, x1, x2) if(false, x0, x1, x2) 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: LE(s(n), s(m)) -> LE(n, m) 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)) le(0, x0) le(s(x0), 0) le(s(x0), s(x1)) min(cons(x0, nil)) min(cons(x0, cons(x1, x2))) if_min(true, cons(x0, cons(x1, x2))) if_min(false, cons(x0, cons(x1, x2))) replace(x0, x1, nil) replace(x0, x1, cons(x2, x3)) if_replace(true, x0, x1, cons(x2, x3)) if_replace(false, x0, x1, cons(x2, x3)) empty(nil) empty(cons(x0, x1)) head(cons(x0, x1)) tail(nil) tail(cons(x0, x1)) sort(x0) sortIter(x0, x1) if(true, x0, x1, x2) if(false, x0, x1, x2) 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)) le(0, x0) le(s(x0), 0) le(s(x0), s(x1)) min(cons(x0, nil)) min(cons(x0, cons(x1, x2))) if_min(true, cons(x0, cons(x1, x2))) if_min(false, cons(x0, cons(x1, x2))) replace(x0, x1, nil) replace(x0, x1, cons(x2, x3)) if_replace(true, x0, x1, cons(x2, x3)) if_replace(false, x0, x1, cons(x2, x3)) empty(nil) empty(cons(x0, x1)) head(cons(x0, x1)) tail(nil) tail(cons(x0, x1)) sort(x0) sortIter(x0, x1) if(true, x0, x1, x2) if(false, x0, x1, x2) ---------------------------------------- (11) Obligation: Q DP problem: The TRS P consists of the following rules: LE(s(n), s(m)) -> LE(n, m) 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: *LE(s(n), s(m)) -> LE(n, m) 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: MIN(cons(n, cons(m, x))) -> IF_MIN(le(n, m), cons(n, cons(m, x))) IF_MIN(true, cons(n, cons(m, x))) -> MIN(cons(n, x)) IF_MIN(false, cons(n, cons(m, x))) -> MIN(cons(m, x)) The TRS R consists of the following rules: eq(0, 0) -> true eq(0, s(m)) -> false eq(s(n), 0) -> false eq(s(n), s(m)) -> eq(n, m) le(0, m) -> true le(s(n), 0) -> false le(s(n), s(m)) -> le(n, m) min(cons(x, nil)) -> x min(cons(n, cons(m, x))) -> if_min(le(n, m), cons(n, cons(m, x))) if_min(true, cons(n, cons(m, x))) -> min(cons(n, x)) if_min(false, cons(n, cons(m, x))) -> min(cons(m, x)) replace(n, m, nil) -> nil replace(n, m, cons(k, x)) -> if_replace(eq(n, k), n, m, cons(k, x)) if_replace(true, n, m, cons(k, x)) -> cons(m, x) if_replace(false, n, m, cons(k, x)) -> cons(k, replace(n, m, x)) empty(nil) -> true empty(cons(n, x)) -> false head(cons(n, x)) -> n tail(nil) -> nil tail(cons(n, x)) -> x sort(x) -> sortIter(x, nil) sortIter(x, y) -> if(empty(x), x, y, append(y, cons(min(x), nil))) if(true, x, y, z) -> y if(false, x, y, z) -> sortIter(replace(min(x), head(x), tail(x)), z) The set Q consists of the following terms: eq(0, 0) eq(0, s(x0)) eq(s(x0), 0) eq(s(x0), s(x1)) le(0, x0) le(s(x0), 0) le(s(x0), s(x1)) min(cons(x0, nil)) min(cons(x0, cons(x1, x2))) if_min(true, cons(x0, cons(x1, x2))) if_min(false, cons(x0, cons(x1, x2))) replace(x0, x1, nil) replace(x0, x1, cons(x2, x3)) if_replace(true, x0, x1, cons(x2, x3)) if_replace(false, x0, x1, cons(x2, x3)) empty(nil) empty(cons(x0, x1)) head(cons(x0, x1)) tail(nil) tail(cons(x0, x1)) sort(x0) sortIter(x0, x1) if(true, x0, x1, x2) if(false, x0, x1, x2) 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: MIN(cons(n, cons(m, x))) -> IF_MIN(le(n, m), cons(n, cons(m, x))) IF_MIN(true, cons(n, cons(m, x))) -> MIN(cons(n, x)) IF_MIN(false, cons(n, cons(m, x))) -> MIN(cons(m, x)) The TRS R consists of the following rules: le(0, m) -> true le(s(n), 0) -> false le(s(n), s(m)) -> le(n, m) The set Q consists of the following terms: eq(0, 0) eq(0, s(x0)) eq(s(x0), 0) eq(s(x0), s(x1)) le(0, x0) le(s(x0), 0) le(s(x0), s(x1)) min(cons(x0, nil)) min(cons(x0, cons(x1, x2))) if_min(true, cons(x0, cons(x1, x2))) if_min(false, cons(x0, cons(x1, x2))) replace(x0, x1, nil) replace(x0, x1, cons(x2, x3)) if_replace(true, x0, x1, cons(x2, x3)) if_replace(false, x0, x1, cons(x2, x3)) empty(nil) empty(cons(x0, x1)) head(cons(x0, x1)) tail(nil) tail(cons(x0, x1)) sort(x0) sortIter(x0, x1) if(true, x0, x1, x2) if(false, x0, x1, x2) 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]. eq(0, 0) eq(0, s(x0)) eq(s(x0), 0) eq(s(x0), s(x1)) min(cons(x0, nil)) min(cons(x0, cons(x1, x2))) if_min(true, cons(x0, cons(x1, x2))) if_min(false, cons(x0, cons(x1, x2))) replace(x0, x1, nil) replace(x0, x1, cons(x2, x3)) if_replace(true, x0, x1, cons(x2, x3)) if_replace(false, x0, x1, cons(x2, x3)) empty(nil) empty(cons(x0, x1)) head(cons(x0, x1)) tail(nil) tail(cons(x0, x1)) sort(x0) sortIter(x0, x1) if(true, x0, x1, x2) if(false, x0, x1, x2) ---------------------------------------- (18) Obligation: Q DP problem: The TRS P consists of the following rules: MIN(cons(n, cons(m, x))) -> IF_MIN(le(n, m), cons(n, cons(m, x))) IF_MIN(true, cons(n, cons(m, x))) -> MIN(cons(n, x)) IF_MIN(false, cons(n, cons(m, x))) -> MIN(cons(m, x)) The TRS R consists of the following rules: le(0, m) -> true le(s(n), 0) -> false le(s(n), s(m)) -> le(n, m) The set Q consists of the following terms: le(0, x0) le(s(x0), 0) le(s(x0), s(x1)) 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. IF_MIN(true, cons(n, cons(m, x))) -> MIN(cons(n, x)) IF_MIN(false, cons(n, cons(m, x))) -> MIN(cons(m, x)) The remaining pairs can at least be oriented weakly. Used ordering: Combined order from the following AFS and order. MIN(x1) = x1 cons(x1, x2) = cons(x2) IF_MIN(x1, x2) = x2 Knuth-Bendix order [KBO] with precedence:trivial and weight map: dummyConstant=1 cons_1=1 The following usable rules [FROCOS05] with respect to the argument filtering of the ordering [JAR06] were oriented: none ---------------------------------------- (20) Obligation: Q DP problem: The TRS P consists of the following rules: MIN(cons(n, cons(m, x))) -> IF_MIN(le(n, m), cons(n, cons(m, x))) The TRS R consists of the following rules: le(0, m) -> true le(s(n), 0) -> false le(s(n), s(m)) -> le(n, m) The set Q consists of the following terms: le(0, x0) le(s(x0), 0) le(s(x0), s(x1)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (21) DependencyGraphProof (EQUIVALENT) The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 0 SCCs with 1 less node. ---------------------------------------- (22) TRUE ---------------------------------------- (23) Obligation: Q DP problem: The TRS P consists of the following rules: EQ(s(n), s(m)) -> EQ(n, m) The TRS R consists of the following rules: eq(0, 0) -> true eq(0, s(m)) -> false eq(s(n), 0) -> false eq(s(n), s(m)) -> eq(n, m) le(0, m) -> true le(s(n), 0) -> false le(s(n), s(m)) -> le(n, m) min(cons(x, nil)) -> x min(cons(n, cons(m, x))) -> if_min(le(n, m), cons(n, cons(m, x))) if_min(true, cons(n, cons(m, x))) -> min(cons(n, x)) if_min(false, cons(n, cons(m, x))) -> min(cons(m, x)) replace(n, m, nil) -> nil replace(n, m, cons(k, x)) -> if_replace(eq(n, k), n, m, cons(k, x)) if_replace(true, n, m, cons(k, x)) -> cons(m, x) if_replace(false, n, m, cons(k, x)) -> cons(k, replace(n, m, x)) empty(nil) -> true empty(cons(n, x)) -> false head(cons(n, x)) -> n tail(nil) -> nil tail(cons(n, x)) -> x sort(x) -> sortIter(x, nil) sortIter(x, y) -> if(empty(x), x, y, append(y, cons(min(x), nil))) if(true, x, y, z) -> y if(false, x, y, z) -> sortIter(replace(min(x), head(x), tail(x)), z) The set Q consists of the following terms: eq(0, 0) eq(0, s(x0)) eq(s(x0), 0) eq(s(x0), s(x1)) le(0, x0) le(s(x0), 0) le(s(x0), s(x1)) min(cons(x0, nil)) min(cons(x0, cons(x1, x2))) if_min(true, cons(x0, cons(x1, x2))) if_min(false, cons(x0, cons(x1, x2))) replace(x0, x1, nil) replace(x0, x1, cons(x2, x3)) if_replace(true, x0, x1, cons(x2, x3)) if_replace(false, x0, x1, cons(x2, x3)) empty(nil) empty(cons(x0, x1)) head(cons(x0, x1)) tail(nil) tail(cons(x0, x1)) sort(x0) sortIter(x0, x1) if(true, x0, x1, x2) if(false, x0, x1, x2) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (24) 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. ---------------------------------------- (25) Obligation: Q DP problem: The TRS P consists of the following rules: EQ(s(n), s(m)) -> EQ(n, m) 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)) le(0, x0) le(s(x0), 0) le(s(x0), s(x1)) min(cons(x0, nil)) min(cons(x0, cons(x1, x2))) if_min(true, cons(x0, cons(x1, x2))) if_min(false, cons(x0, cons(x1, x2))) replace(x0, x1, nil) replace(x0, x1, cons(x2, x3)) if_replace(true, x0, x1, cons(x2, x3)) if_replace(false, x0, x1, cons(x2, x3)) empty(nil) empty(cons(x0, x1)) head(cons(x0, x1)) tail(nil) tail(cons(x0, x1)) sort(x0) sortIter(x0, x1) if(true, x0, x1, x2) if(false, x0, x1, x2) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (26) 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)) le(0, x0) le(s(x0), 0) le(s(x0), s(x1)) min(cons(x0, nil)) min(cons(x0, cons(x1, x2))) if_min(true, cons(x0, cons(x1, x2))) if_min(false, cons(x0, cons(x1, x2))) replace(x0, x1, nil) replace(x0, x1, cons(x2, x3)) if_replace(true, x0, x1, cons(x2, x3)) if_replace(false, x0, x1, cons(x2, x3)) empty(nil) empty(cons(x0, x1)) head(cons(x0, x1)) tail(nil) tail(cons(x0, x1)) sort(x0) sortIter(x0, x1) if(true, x0, x1, x2) if(false, x0, x1, x2) ---------------------------------------- (27) Obligation: Q DP problem: The TRS P consists of the following rules: EQ(s(n), s(m)) -> EQ(n, m) 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: *EQ(s(n), s(m)) -> EQ(n, m) 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: REPLACE(n, m, cons(k, x)) -> IF_REPLACE(eq(n, k), n, m, cons(k, x)) IF_REPLACE(false, n, m, cons(k, x)) -> REPLACE(n, m, x) The TRS R consists of the following rules: eq(0, 0) -> true eq(0, s(m)) -> false eq(s(n), 0) -> false eq(s(n), s(m)) -> eq(n, m) le(0, m) -> true le(s(n), 0) -> false le(s(n), s(m)) -> le(n, m) min(cons(x, nil)) -> x min(cons(n, cons(m, x))) -> if_min(le(n, m), cons(n, cons(m, x))) if_min(true, cons(n, cons(m, x))) -> min(cons(n, x)) if_min(false, cons(n, cons(m, x))) -> min(cons(m, x)) replace(n, m, nil) -> nil replace(n, m, cons(k, x)) -> if_replace(eq(n, k), n, m, cons(k, x)) if_replace(true, n, m, cons(k, x)) -> cons(m, x) if_replace(false, n, m, cons(k, x)) -> cons(k, replace(n, m, x)) empty(nil) -> true empty(cons(n, x)) -> false head(cons(n, x)) -> n tail(nil) -> nil tail(cons(n, x)) -> x sort(x) -> sortIter(x, nil) sortIter(x, y) -> if(empty(x), x, y, append(y, cons(min(x), nil))) if(true, x, y, z) -> y if(false, x, y, z) -> sortIter(replace(min(x), head(x), tail(x)), z) The set Q consists of the following terms: eq(0, 0) eq(0, s(x0)) eq(s(x0), 0) eq(s(x0), s(x1)) le(0, x0) le(s(x0), 0) le(s(x0), s(x1)) min(cons(x0, nil)) min(cons(x0, cons(x1, x2))) if_min(true, cons(x0, cons(x1, x2))) if_min(false, cons(x0, cons(x1, x2))) replace(x0, x1, nil) replace(x0, x1, cons(x2, x3)) if_replace(true, x0, x1, cons(x2, x3)) if_replace(false, x0, x1, cons(x2, x3)) empty(nil) empty(cons(x0, x1)) head(cons(x0, x1)) tail(nil) tail(cons(x0, x1)) sort(x0) sortIter(x0, x1) if(true, x0, x1, x2) if(false, x0, x1, x2) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (31) 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. ---------------------------------------- (32) Obligation: Q DP problem: The TRS P consists of the following rules: REPLACE(n, m, cons(k, x)) -> IF_REPLACE(eq(n, k), n, m, cons(k, x)) IF_REPLACE(false, n, m, cons(k, x)) -> REPLACE(n, m, x) The TRS R consists of the following rules: eq(0, 0) -> true eq(0, s(m)) -> false eq(s(n), 0) -> false eq(s(n), s(m)) -> eq(n, m) The set Q consists of the following terms: eq(0, 0) eq(0, s(x0)) eq(s(x0), 0) eq(s(x0), s(x1)) le(0, x0) le(s(x0), 0) le(s(x0), s(x1)) min(cons(x0, nil)) min(cons(x0, cons(x1, x2))) if_min(true, cons(x0, cons(x1, x2))) if_min(false, cons(x0, cons(x1, x2))) replace(x0, x1, nil) replace(x0, x1, cons(x2, x3)) if_replace(true, x0, x1, cons(x2, x3)) if_replace(false, x0, x1, cons(x2, x3)) empty(nil) empty(cons(x0, x1)) head(cons(x0, x1)) tail(nil) tail(cons(x0, x1)) sort(x0) sortIter(x0, x1) if(true, x0, x1, x2) if(false, x0, x1, x2) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (33) 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]. le(0, x0) le(s(x0), 0) le(s(x0), s(x1)) min(cons(x0, nil)) min(cons(x0, cons(x1, x2))) if_min(true, cons(x0, cons(x1, x2))) if_min(false, cons(x0, cons(x1, x2))) replace(x0, x1, nil) replace(x0, x1, cons(x2, x3)) if_replace(true, x0, x1, cons(x2, x3)) if_replace(false, x0, x1, cons(x2, x3)) empty(nil) empty(cons(x0, x1)) head(cons(x0, x1)) tail(nil) tail(cons(x0, x1)) sort(x0) sortIter(x0, x1) if(true, x0, x1, x2) if(false, x0, x1, x2) ---------------------------------------- (34) Obligation: Q DP problem: The TRS P consists of the following rules: REPLACE(n, m, cons(k, x)) -> IF_REPLACE(eq(n, k), n, m, cons(k, x)) IF_REPLACE(false, n, m, cons(k, x)) -> REPLACE(n, m, x) The TRS R consists of the following rules: eq(0, 0) -> true eq(0, s(m)) -> false eq(s(n), 0) -> false eq(s(n), s(m)) -> eq(n, m) 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. ---------------------------------------- (35) 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: *IF_REPLACE(false, n, m, cons(k, x)) -> REPLACE(n, m, x) The graph contains the following edges 2 >= 1, 3 >= 2, 4 > 3 *REPLACE(n, m, cons(k, x)) -> IF_REPLACE(eq(n, k), n, m, cons(k, x)) The graph contains the following edges 1 >= 2, 2 >= 3, 3 >= 4 ---------------------------------------- (36) YES ---------------------------------------- (37) Obligation: Q DP problem: The TRS P consists of the following rules: IF(false, x, y, z) -> SORTITER(replace(min(x), head(x), tail(x)), z) SORTITER(x, y) -> IF(empty(x), x, y, append(y, cons(min(x), nil))) The TRS R consists of the following rules: eq(0, 0) -> true eq(0, s(m)) -> false eq(s(n), 0) -> false eq(s(n), s(m)) -> eq(n, m) le(0, m) -> true le(s(n), 0) -> false le(s(n), s(m)) -> le(n, m) min(cons(x, nil)) -> x min(cons(n, cons(m, x))) -> if_min(le(n, m), cons(n, cons(m, x))) if_min(true, cons(n, cons(m, x))) -> min(cons(n, x)) if_min(false, cons(n, cons(m, x))) -> min(cons(m, x)) replace(n, m, nil) -> nil replace(n, m, cons(k, x)) -> if_replace(eq(n, k), n, m, cons(k, x)) if_replace(true, n, m, cons(k, x)) -> cons(m, x) if_replace(false, n, m, cons(k, x)) -> cons(k, replace(n, m, x)) empty(nil) -> true empty(cons(n, x)) -> false head(cons(n, x)) -> n tail(nil) -> nil tail(cons(n, x)) -> x sort(x) -> sortIter(x, nil) sortIter(x, y) -> if(empty(x), x, y, append(y, cons(min(x), nil))) if(true, x, y, z) -> y if(false, x, y, z) -> sortIter(replace(min(x), head(x), tail(x)), z) The set Q consists of the following terms: eq(0, 0) eq(0, s(x0)) eq(s(x0), 0) eq(s(x0), s(x1)) le(0, x0) le(s(x0), 0) le(s(x0), s(x1)) min(cons(x0, nil)) min(cons(x0, cons(x1, x2))) if_min(true, cons(x0, cons(x1, x2))) if_min(false, cons(x0, cons(x1, x2))) replace(x0, x1, nil) replace(x0, x1, cons(x2, x3)) if_replace(true, x0, x1, cons(x2, x3)) if_replace(false, x0, x1, cons(x2, x3)) empty(nil) empty(cons(x0, x1)) head(cons(x0, x1)) tail(nil) tail(cons(x0, x1)) sort(x0) sortIter(x0, x1) if(true, x0, x1, x2) if(false, x0, x1, x2) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (38) 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. ---------------------------------------- (39) Obligation: Q DP problem: The TRS P consists of the following rules: IF(false, x, y, z) -> SORTITER(replace(min(x), head(x), tail(x)), z) SORTITER(x, y) -> IF(empty(x), x, y, append(y, cons(min(x), nil))) The TRS R consists of the following rules: empty(nil) -> true empty(cons(n, x)) -> false min(cons(x, nil)) -> x min(cons(n, cons(m, x))) -> if_min(le(n, m), cons(n, cons(m, x))) if_min(true, cons(n, cons(m, x))) -> min(cons(n, x)) if_min(false, cons(n, cons(m, x))) -> min(cons(m, x)) le(0, m) -> true le(s(n), 0) -> false le(s(n), s(m)) -> le(n, m) head(cons(n, x)) -> n tail(nil) -> nil tail(cons(n, x)) -> x replace(n, m, nil) -> nil replace(n, m, cons(k, x)) -> if_replace(eq(n, k), n, m, cons(k, x)) eq(0, 0) -> true eq(0, s(m)) -> false eq(s(n), 0) -> false eq(s(n), s(m)) -> eq(n, m) if_replace(true, n, m, cons(k, x)) -> cons(m, x) if_replace(false, n, m, cons(k, x)) -> cons(k, replace(n, m, 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)) le(0, x0) le(s(x0), 0) le(s(x0), s(x1)) min(cons(x0, nil)) min(cons(x0, cons(x1, x2))) if_min(true, cons(x0, cons(x1, x2))) if_min(false, cons(x0, cons(x1, x2))) replace(x0, x1, nil) replace(x0, x1, cons(x2, x3)) if_replace(true, x0, x1, cons(x2, x3)) if_replace(false, x0, x1, cons(x2, x3)) empty(nil) empty(cons(x0, x1)) head(cons(x0, x1)) tail(nil) tail(cons(x0, x1)) sort(x0) sortIter(x0, x1) if(true, x0, x1, x2) if(false, x0, x1, x2) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (40) 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]. sort(x0) sortIter(x0, x1) if(true, x0, x1, x2) if(false, x0, x1, x2) ---------------------------------------- (41) Obligation: Q DP problem: The TRS P consists of the following rules: IF(false, x, y, z) -> SORTITER(replace(min(x), head(x), tail(x)), z) SORTITER(x, y) -> IF(empty(x), x, y, append(y, cons(min(x), nil))) The TRS R consists of the following rules: empty(nil) -> true empty(cons(n, x)) -> false min(cons(x, nil)) -> x min(cons(n, cons(m, x))) -> if_min(le(n, m), cons(n, cons(m, x))) if_min(true, cons(n, cons(m, x))) -> min(cons(n, x)) if_min(false, cons(n, cons(m, x))) -> min(cons(m, x)) le(0, m) -> true le(s(n), 0) -> false le(s(n), s(m)) -> le(n, m) head(cons(n, x)) -> n tail(nil) -> nil tail(cons(n, x)) -> x replace(n, m, nil) -> nil replace(n, m, cons(k, x)) -> if_replace(eq(n, k), n, m, cons(k, x)) eq(0, 0) -> true eq(0, s(m)) -> false eq(s(n), 0) -> false eq(s(n), s(m)) -> eq(n, m) if_replace(true, n, m, cons(k, x)) -> cons(m, x) if_replace(false, n, m, cons(k, x)) -> cons(k, replace(n, m, 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)) le(0, x0) le(s(x0), 0) le(s(x0), s(x1)) min(cons(x0, nil)) min(cons(x0, cons(x1, x2))) if_min(true, cons(x0, cons(x1, x2))) if_min(false, cons(x0, cons(x1, x2))) replace(x0, x1, nil) replace(x0, x1, cons(x2, x3)) if_replace(true, x0, x1, cons(x2, x3)) if_replace(false, x0, x1, cons(x2, x3)) empty(nil) empty(cons(x0, x1)) head(cons(x0, x1)) tail(nil) tail(cons(x0, x1)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (42) QDPOrderProof (EQUIVALENT) We use the reduction pair processor [LPAR04,JAR06]. The following pairs can be oriented strictly and are deleted. IF(false, x, y, z) -> SORTITER(replace(min(x), head(x), tail(x)), z) SORTITER(x, y) -> IF(empty(x), x, y, append(y, cons(min(x), nil))) The remaining pairs can at least be oriented weakly. Used ordering: Polynomial interpretation [POLO,RATPOLO]: POL(0) = 0 POL(IF(x_1, x_2, x_3, x_4)) = [1/2]x_1 + [1/4]x_2 POL(SORTITER(x_1, x_2)) = [1/4] + [1/2]x_1 POL(append(x_1, x_2)) = 0 POL(cons(x_1, x_2)) = [2] + [4]x_2 POL(empty(x_1)) = [1/2]x_1 POL(eq(x_1, x_2)) = 0 POL(false) = [1] POL(head(x_1)) = 0 POL(if_min(x_1, x_2)) = [1] POL(if_replace(x_1, x_2, x_3, x_4)) = [2]x_4 POL(le(x_1, x_2)) = [4] POL(min(x_1)) = 0 POL(nil) = 0 POL(replace(x_1, x_2, x_3)) = [2]x_3 POL(s(x_1)) = 0 POL(tail(x_1)) = [1/4]x_1 POL(true) = 0 The value of delta used in the strict ordering is 1/4. The following usable rules [FROCOS05] with respect to the argument filtering of the ordering [JAR06] were oriented: tail(nil) -> nil tail(cons(n, x)) -> x replace(n, m, nil) -> nil replace(n, m, cons(k, x)) -> if_replace(eq(n, k), n, m, cons(k, x)) empty(nil) -> true empty(cons(n, x)) -> false if_replace(true, n, m, cons(k, x)) -> cons(m, x) if_replace(false, n, m, cons(k, x)) -> cons(k, replace(n, m, x)) ---------------------------------------- (43) Obligation: Q DP problem: P is empty. The TRS R consists of the following rules: empty(nil) -> true empty(cons(n, x)) -> false min(cons(x, nil)) -> x min(cons(n, cons(m, x))) -> if_min(le(n, m), cons(n, cons(m, x))) if_min(true, cons(n, cons(m, x))) -> min(cons(n, x)) if_min(false, cons(n, cons(m, x))) -> min(cons(m, x)) le(0, m) -> true le(s(n), 0) -> false le(s(n), s(m)) -> le(n, m) head(cons(n, x)) -> n tail(nil) -> nil tail(cons(n, x)) -> x replace(n, m, nil) -> nil replace(n, m, cons(k, x)) -> if_replace(eq(n, k), n, m, cons(k, x)) eq(0, 0) -> true eq(0, s(m)) -> false eq(s(n), 0) -> false eq(s(n), s(m)) -> eq(n, m) if_replace(true, n, m, cons(k, x)) -> cons(m, x) if_replace(false, n, m, cons(k, x)) -> cons(k, replace(n, m, 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)) le(0, x0) le(s(x0), 0) le(s(x0), s(x1)) min(cons(x0, nil)) min(cons(x0, cons(x1, x2))) if_min(true, cons(x0, cons(x1, x2))) if_min(false, cons(x0, cons(x1, x2))) replace(x0, x1, nil) replace(x0, x1, cons(x2, x3)) if_replace(true, x0, x1, cons(x2, x3)) if_replace(false, x0, x1, cons(x2, x3)) empty(nil) empty(cons(x0, x1)) head(cons(x0, x1)) tail(nil) tail(cons(x0, x1)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (44) PisEmptyProof (EQUIVALENT) The TRS P is empty. Hence, there is no (P,Q,R) chain. ---------------------------------------- (45) YES