/export/starexec/sandbox/solver/bin/starexec_run_standard /export/starexec/sandbox/benchmark/theBenchmark.xml /export/starexec/sandbox/output/output_files -------------------------------------------------------------------------------- YES proof of /export/starexec/sandbox/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# AProVE Commit ID: 48fb2092695e11cc9f56e44b17a92a5f88ffb256 marcel 20180622 unpublished dirty Termination w.r.t. Q of the given QTRS could be proven: (0) QTRS (1) Overlay + Local Confluence [EQUIVALENT, 13 ms] (2) QTRS (3) DependencyPairsProof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) TransformationProof [EQUIVALENT, 0 ms] (34) QDP (35) DependencyGraphProof [EQUIVALENT, 0 ms] (36) QDP (37) TransformationProof [EQUIVALENT, 0 ms] (38) QDP (39) DependencyGraphProof [EQUIVALENT, 0 ms] (40) QDP (41) TransformationProof [EQUIVALENT, 0 ms] (42) QDP (43) TransformationProof [EQUIVALENT, 0 ms] (44) QDP (45) Induction-Processor [SOUND, 45 ms] (46) AND (47) QDP (48) DependencyGraphProof [EQUIVALENT, 0 ms] (49) TRUE (50) QTRS (51) QTRSRRRProof [EQUIVALENT, 76 ms] (52) QTRS (53) RisEmptyProof [EQUIVALENT, 0 ms] (54) YES ---------------------------------------- (0) Obligation: Q restricted rewrite system: The TRS R consists of the following rules: minus(0, y) -> 0 minus(s(x), y) -> if(gt(s(x), y), x, y) if(true, x, y) -> s(minus(x, y)) if(false, x, y) -> 0 mod(x, 0) -> 0 mod(x, s(y)) -> if1(lt(x, s(y)), x, s(y)) if1(true, x, y) -> x if1(false, x, y) -> mod(minus(x, y), y) gt(0, y) -> false gt(s(x), 0) -> true gt(s(x), s(y)) -> gt(x, y) lt(x, 0) -> false lt(0, s(x)) -> true lt(s(x), s(y)) -> lt(x, y) 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: minus(0, y) -> 0 minus(s(x), y) -> if(gt(s(x), y), x, y) if(true, x, y) -> s(minus(x, y)) if(false, x, y) -> 0 mod(x, 0) -> 0 mod(x, s(y)) -> if1(lt(x, s(y)), x, s(y)) if1(true, x, y) -> x if1(false, x, y) -> mod(minus(x, y), y) gt(0, y) -> false gt(s(x), 0) -> true gt(s(x), s(y)) -> gt(x, y) lt(x, 0) -> false lt(0, s(x)) -> true lt(s(x), s(y)) -> lt(x, y) The set Q consists of the following terms: minus(0, x0) minus(s(x0), x1) if(true, x0, x1) if(false, x0, x1) mod(x0, 0) mod(x0, s(x1)) if1(true, x0, x1) if1(false, x0, x1) gt(0, x0) gt(s(x0), 0) gt(s(x0), s(x1)) lt(x0, 0) lt(0, s(x0)) lt(s(x0), s(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: MINUS(s(x), y) -> IF(gt(s(x), y), x, y) MINUS(s(x), y) -> GT(s(x), y) IF(true, x, y) -> MINUS(x, y) MOD(x, s(y)) -> IF1(lt(x, s(y)), x, s(y)) MOD(x, s(y)) -> LT(x, s(y)) IF1(false, x, y) -> MOD(minus(x, y), y) IF1(false, x, y) -> MINUS(x, y) GT(s(x), s(y)) -> GT(x, y) LT(s(x), s(y)) -> LT(x, y) The TRS R consists of the following rules: minus(0, y) -> 0 minus(s(x), y) -> if(gt(s(x), y), x, y) if(true, x, y) -> s(minus(x, y)) if(false, x, y) -> 0 mod(x, 0) -> 0 mod(x, s(y)) -> if1(lt(x, s(y)), x, s(y)) if1(true, x, y) -> x if1(false, x, y) -> mod(minus(x, y), y) gt(0, y) -> false gt(s(x), 0) -> true gt(s(x), s(y)) -> gt(x, y) lt(x, 0) -> false lt(0, s(x)) -> true lt(s(x), s(y)) -> lt(x, y) The set Q consists of the following terms: minus(0, x0) minus(s(x0), x1) if(true, x0, x1) if(false, x0, x1) mod(x0, 0) mod(x0, s(x1)) if1(true, x0, x1) if1(false, x0, x1) gt(0, x0) gt(s(x0), 0) gt(s(x0), s(x1)) lt(x0, 0) lt(0, s(x0)) lt(s(x0), s(x1)) 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 3 less nodes. ---------------------------------------- (6) Complex Obligation (AND) ---------------------------------------- (7) 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: minus(0, y) -> 0 minus(s(x), y) -> if(gt(s(x), y), x, y) if(true, x, y) -> s(minus(x, y)) if(false, x, y) -> 0 mod(x, 0) -> 0 mod(x, s(y)) -> if1(lt(x, s(y)), x, s(y)) if1(true, x, y) -> x if1(false, x, y) -> mod(minus(x, y), y) gt(0, y) -> false gt(s(x), 0) -> true gt(s(x), s(y)) -> gt(x, y) lt(x, 0) -> false lt(0, s(x)) -> true lt(s(x), s(y)) -> lt(x, y) The set Q consists of the following terms: minus(0, x0) minus(s(x0), x1) if(true, x0, x1) if(false, x0, x1) mod(x0, 0) mod(x0, s(x1)) if1(true, x0, x1) if1(false, x0, x1) gt(0, x0) gt(s(x0), 0) gt(s(x0), s(x1)) lt(x0, 0) lt(0, s(x0)) lt(s(x0), s(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: LT(s(x), s(y)) -> LT(x, y) R is empty. The set Q consists of the following terms: minus(0, x0) minus(s(x0), x1) if(true, x0, x1) if(false, x0, x1) mod(x0, 0) mod(x0, s(x1)) if1(true, x0, x1) if1(false, x0, x1) gt(0, x0) gt(s(x0), 0) gt(s(x0), s(x1)) lt(x0, 0) lt(0, s(x0)) lt(s(x0), s(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]. minus(0, x0) minus(s(x0), x1) if(true, x0, x1) if(false, x0, x1) mod(x0, 0) mod(x0, s(x1)) if1(true, x0, x1) if1(false, x0, x1) gt(0, x0) gt(s(x0), 0) gt(s(x0), s(x1)) lt(x0, 0) lt(0, s(x0)) lt(s(x0), s(x1)) ---------------------------------------- (11) 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. ---------------------------------------- (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: *LT(s(x), s(y)) -> LT(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: GT(s(x), s(y)) -> GT(x, y) The TRS R consists of the following rules: minus(0, y) -> 0 minus(s(x), y) -> if(gt(s(x), y), x, y) if(true, x, y) -> s(minus(x, y)) if(false, x, y) -> 0 mod(x, 0) -> 0 mod(x, s(y)) -> if1(lt(x, s(y)), x, s(y)) if1(true, x, y) -> x if1(false, x, y) -> mod(minus(x, y), y) gt(0, y) -> false gt(s(x), 0) -> true gt(s(x), s(y)) -> gt(x, y) lt(x, 0) -> false lt(0, s(x)) -> true lt(s(x), s(y)) -> lt(x, y) The set Q consists of the following terms: minus(0, x0) minus(s(x0), x1) if(true, x0, x1) if(false, x0, x1) mod(x0, 0) mod(x0, s(x1)) if1(true, x0, x1) if1(false, x0, x1) gt(0, x0) gt(s(x0), 0) gt(s(x0), s(x1)) lt(x0, 0) lt(0, s(x0)) lt(s(x0), s(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: GT(s(x), s(y)) -> GT(x, y) R is empty. The set Q consists of the following terms: minus(0, x0) minus(s(x0), x1) if(true, x0, x1) if(false, x0, x1) mod(x0, 0) mod(x0, s(x1)) if1(true, x0, x1) if1(false, x0, x1) gt(0, x0) gt(s(x0), 0) gt(s(x0), s(x1)) lt(x0, 0) lt(0, s(x0)) lt(s(x0), s(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]. minus(0, x0) minus(s(x0), x1) if(true, x0, x1) if(false, x0, x1) mod(x0, 0) mod(x0, s(x1)) if1(true, x0, x1) if1(false, x0, x1) gt(0, x0) gt(s(x0), 0) gt(s(x0), s(x1)) lt(x0, 0) lt(0, s(x0)) lt(s(x0), s(x1)) ---------------------------------------- (18) Obligation: Q DP problem: The TRS P consists of the following rules: GT(s(x), s(y)) -> GT(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: *GT(s(x), s(y)) -> GT(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: IF(true, x, y) -> MINUS(x, y) MINUS(s(x), y) -> IF(gt(s(x), y), x, y) The TRS R consists of the following rules: minus(0, y) -> 0 minus(s(x), y) -> if(gt(s(x), y), x, y) if(true, x, y) -> s(minus(x, y)) if(false, x, y) -> 0 mod(x, 0) -> 0 mod(x, s(y)) -> if1(lt(x, s(y)), x, s(y)) if1(true, x, y) -> x if1(false, x, y) -> mod(minus(x, y), y) gt(0, y) -> false gt(s(x), 0) -> true gt(s(x), s(y)) -> gt(x, y) lt(x, 0) -> false lt(0, s(x)) -> true lt(s(x), s(y)) -> lt(x, y) The set Q consists of the following terms: minus(0, x0) minus(s(x0), x1) if(true, x0, x1) if(false, x0, x1) mod(x0, 0) mod(x0, s(x1)) if1(true, x0, x1) if1(false, x0, x1) gt(0, x0) gt(s(x0), 0) gt(s(x0), s(x1)) lt(x0, 0) lt(0, s(x0)) lt(s(x0), s(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: IF(true, x, y) -> MINUS(x, y) MINUS(s(x), y) -> IF(gt(s(x), y), x, y) The TRS R consists of the following rules: gt(s(x), 0) -> true gt(s(x), s(y)) -> gt(x, y) gt(0, y) -> false The set Q consists of the following terms: minus(0, x0) minus(s(x0), x1) if(true, x0, x1) if(false, x0, x1) mod(x0, 0) mod(x0, s(x1)) if1(true, x0, x1) if1(false, x0, x1) gt(0, x0) gt(s(x0), 0) gt(s(x0), s(x1)) lt(x0, 0) lt(0, s(x0)) lt(s(x0), s(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]. minus(0, x0) minus(s(x0), x1) if(true, x0, x1) if(false, x0, x1) mod(x0, 0) mod(x0, s(x1)) if1(true, x0, x1) if1(false, x0, x1) lt(x0, 0) lt(0, s(x0)) lt(s(x0), s(x1)) ---------------------------------------- (25) Obligation: Q DP problem: The TRS P consists of the following rules: IF(true, x, y) -> MINUS(x, y) MINUS(s(x), y) -> IF(gt(s(x), y), x, y) The TRS R consists of the following rules: gt(s(x), 0) -> true gt(s(x), s(y)) -> gt(x, y) gt(0, y) -> false The set Q consists of the following terms: gt(0, x0) gt(s(x0), 0) gt(s(x0), s(x1)) 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: *MINUS(s(x), y) -> IF(gt(s(x), y), x, y) The graph contains the following edges 1 > 2, 2 >= 3 *IF(true, x, y) -> MINUS(x, y) The graph contains the following edges 2 >= 1, 3 >= 2 ---------------------------------------- (27) YES ---------------------------------------- (28) Obligation: Q DP problem: The TRS P consists of the following rules: IF1(false, x, y) -> MOD(minus(x, y), y) MOD(x, s(y)) -> IF1(lt(x, s(y)), x, s(y)) The TRS R consists of the following rules: minus(0, y) -> 0 minus(s(x), y) -> if(gt(s(x), y), x, y) if(true, x, y) -> s(minus(x, y)) if(false, x, y) -> 0 mod(x, 0) -> 0 mod(x, s(y)) -> if1(lt(x, s(y)), x, s(y)) if1(true, x, y) -> x if1(false, x, y) -> mod(minus(x, y), y) gt(0, y) -> false gt(s(x), 0) -> true gt(s(x), s(y)) -> gt(x, y) lt(x, 0) -> false lt(0, s(x)) -> true lt(s(x), s(y)) -> lt(x, y) The set Q consists of the following terms: minus(0, x0) minus(s(x0), x1) if(true, x0, x1) if(false, x0, x1) mod(x0, 0) mod(x0, s(x1)) if1(true, x0, x1) if1(false, x0, x1) gt(0, x0) gt(s(x0), 0) gt(s(x0), s(x1)) lt(x0, 0) lt(0, s(x0)) lt(s(x0), s(x1)) 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: IF1(false, x, y) -> MOD(minus(x, y), y) MOD(x, s(y)) -> IF1(lt(x, s(y)), x, s(y)) The TRS R consists of the following rules: lt(0, s(x)) -> true lt(s(x), s(y)) -> lt(x, y) lt(x, 0) -> false minus(0, y) -> 0 minus(s(x), y) -> if(gt(s(x), y), x, y) gt(s(x), 0) -> true gt(s(x), s(y)) -> gt(x, y) if(true, x, y) -> s(minus(x, y)) if(false, x, y) -> 0 gt(0, y) -> false The set Q consists of the following terms: minus(0, x0) minus(s(x0), x1) if(true, x0, x1) if(false, x0, x1) mod(x0, 0) mod(x0, s(x1)) if1(true, x0, x1) if1(false, x0, x1) gt(0, x0) gt(s(x0), 0) gt(s(x0), s(x1)) lt(x0, 0) lt(0, s(x0)) lt(s(x0), s(x1)) 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]. mod(x0, 0) mod(x0, s(x1)) if1(true, x0, x1) if1(false, x0, x1) ---------------------------------------- (32) Obligation: Q DP problem: The TRS P consists of the following rules: IF1(false, x, y) -> MOD(minus(x, y), y) MOD(x, s(y)) -> IF1(lt(x, s(y)), x, s(y)) The TRS R consists of the following rules: lt(0, s(x)) -> true lt(s(x), s(y)) -> lt(x, y) lt(x, 0) -> false minus(0, y) -> 0 minus(s(x), y) -> if(gt(s(x), y), x, y) gt(s(x), 0) -> true gt(s(x), s(y)) -> gt(x, y) if(true, x, y) -> s(minus(x, y)) if(false, x, y) -> 0 gt(0, y) -> false The set Q consists of the following terms: minus(0, x0) minus(s(x0), x1) if(true, x0, x1) if(false, x0, x1) gt(0, x0) gt(s(x0), 0) gt(s(x0), s(x1)) lt(x0, 0) lt(0, s(x0)) lt(s(x0), s(x1)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (33) TransformationProof (EQUIVALENT) By narrowing [LPAR04] the rule MOD(x, s(y)) -> IF1(lt(x, s(y)), x, s(y)) at position [0] we obtained the following new rules [LPAR04]: (MOD(0, s(x0)) -> IF1(true, 0, s(x0)),MOD(0, s(x0)) -> IF1(true, 0, s(x0))) (MOD(s(x0), s(x1)) -> IF1(lt(x0, x1), s(x0), s(x1)),MOD(s(x0), s(x1)) -> IF1(lt(x0, x1), s(x0), s(x1))) ---------------------------------------- (34) Obligation: Q DP problem: The TRS P consists of the following rules: IF1(false, x, y) -> MOD(minus(x, y), y) MOD(0, s(x0)) -> IF1(true, 0, s(x0)) MOD(s(x0), s(x1)) -> IF1(lt(x0, x1), s(x0), s(x1)) The TRS R consists of the following rules: lt(0, s(x)) -> true lt(s(x), s(y)) -> lt(x, y) lt(x, 0) -> false minus(0, y) -> 0 minus(s(x), y) -> if(gt(s(x), y), x, y) gt(s(x), 0) -> true gt(s(x), s(y)) -> gt(x, y) if(true, x, y) -> s(minus(x, y)) if(false, x, y) -> 0 gt(0, y) -> false The set Q consists of the following terms: minus(0, x0) minus(s(x0), x1) if(true, x0, x1) if(false, x0, x1) gt(0, x0) gt(s(x0), 0) gt(s(x0), s(x1)) lt(x0, 0) lt(0, s(x0)) lt(s(x0), s(x1)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (35) DependencyGraphProof (EQUIVALENT) The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 1 SCC with 1 less node. ---------------------------------------- (36) Obligation: Q DP problem: The TRS P consists of the following rules: MOD(s(x0), s(x1)) -> IF1(lt(x0, x1), s(x0), s(x1)) IF1(false, x, y) -> MOD(minus(x, y), y) The TRS R consists of the following rules: lt(0, s(x)) -> true lt(s(x), s(y)) -> lt(x, y) lt(x, 0) -> false minus(0, y) -> 0 minus(s(x), y) -> if(gt(s(x), y), x, y) gt(s(x), 0) -> true gt(s(x), s(y)) -> gt(x, y) if(true, x, y) -> s(minus(x, y)) if(false, x, y) -> 0 gt(0, y) -> false The set Q consists of the following terms: minus(0, x0) minus(s(x0), x1) if(true, x0, x1) if(false, x0, x1) gt(0, x0) gt(s(x0), 0) gt(s(x0), s(x1)) lt(x0, 0) lt(0, s(x0)) lt(s(x0), s(x1)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (37) TransformationProof (EQUIVALENT) By narrowing [LPAR04] the rule IF1(false, x, y) -> MOD(minus(x, y), y) at position [0] we obtained the following new rules [LPAR04]: (IF1(false, 0, x0) -> MOD(0, x0),IF1(false, 0, x0) -> MOD(0, x0)) (IF1(false, s(x0), x1) -> MOD(if(gt(s(x0), x1), x0, x1), x1),IF1(false, s(x0), x1) -> MOD(if(gt(s(x0), x1), x0, x1), x1)) ---------------------------------------- (38) Obligation: Q DP problem: The TRS P consists of the following rules: MOD(s(x0), s(x1)) -> IF1(lt(x0, x1), s(x0), s(x1)) IF1(false, 0, x0) -> MOD(0, x0) IF1(false, s(x0), x1) -> MOD(if(gt(s(x0), x1), x0, x1), x1) The TRS R consists of the following rules: lt(0, s(x)) -> true lt(s(x), s(y)) -> lt(x, y) lt(x, 0) -> false minus(0, y) -> 0 minus(s(x), y) -> if(gt(s(x), y), x, y) gt(s(x), 0) -> true gt(s(x), s(y)) -> gt(x, y) if(true, x, y) -> s(minus(x, y)) if(false, x, y) -> 0 gt(0, y) -> false The set Q consists of the following terms: minus(0, x0) minus(s(x0), x1) if(true, x0, x1) if(false, x0, x1) gt(0, x0) gt(s(x0), 0) gt(s(x0), s(x1)) lt(x0, 0) lt(0, s(x0)) lt(s(x0), s(x1)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (39) DependencyGraphProof (EQUIVALENT) The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 1 SCC with 1 less node. ---------------------------------------- (40) Obligation: Q DP problem: The TRS P consists of the following rules: IF1(false, s(x0), x1) -> MOD(if(gt(s(x0), x1), x0, x1), x1) MOD(s(x0), s(x1)) -> IF1(lt(x0, x1), s(x0), s(x1)) The TRS R consists of the following rules: lt(0, s(x)) -> true lt(s(x), s(y)) -> lt(x, y) lt(x, 0) -> false minus(0, y) -> 0 minus(s(x), y) -> if(gt(s(x), y), x, y) gt(s(x), 0) -> true gt(s(x), s(y)) -> gt(x, y) if(true, x, y) -> s(minus(x, y)) if(false, x, y) -> 0 gt(0, y) -> false The set Q consists of the following terms: minus(0, x0) minus(s(x0), x1) if(true, x0, x1) if(false, x0, x1) gt(0, x0) gt(s(x0), 0) gt(s(x0), s(x1)) lt(x0, 0) lt(0, s(x0)) lt(s(x0), s(x1)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (41) TransformationProof (EQUIVALENT) By instantiating [LPAR04] the rule IF1(false, s(x0), x1) -> MOD(if(gt(s(x0), x1), x0, x1), x1) we obtained the following new rules [LPAR04]: (IF1(false, s(z0), s(z1)) -> MOD(if(gt(s(z0), s(z1)), z0, s(z1)), s(z1)),IF1(false, s(z0), s(z1)) -> MOD(if(gt(s(z0), s(z1)), z0, s(z1)), s(z1))) ---------------------------------------- (42) Obligation: Q DP problem: The TRS P consists of the following rules: MOD(s(x0), s(x1)) -> IF1(lt(x0, x1), s(x0), s(x1)) IF1(false, s(z0), s(z1)) -> MOD(if(gt(s(z0), s(z1)), z0, s(z1)), s(z1)) The TRS R consists of the following rules: lt(0, s(x)) -> true lt(s(x), s(y)) -> lt(x, y) lt(x, 0) -> false minus(0, y) -> 0 minus(s(x), y) -> if(gt(s(x), y), x, y) gt(s(x), 0) -> true gt(s(x), s(y)) -> gt(x, y) if(true, x, y) -> s(minus(x, y)) if(false, x, y) -> 0 gt(0, y) -> false The set Q consists of the following terms: minus(0, x0) minus(s(x0), x1) if(true, x0, x1) if(false, x0, x1) gt(0, x0) gt(s(x0), 0) gt(s(x0), s(x1)) lt(x0, 0) lt(0, s(x0)) lt(s(x0), s(x1)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (43) TransformationProof (EQUIVALENT) By rewriting [LPAR04] the rule IF1(false, s(z0), s(z1)) -> MOD(if(gt(s(z0), s(z1)), z0, s(z1)), s(z1)) at position [0,0] we obtained the following new rules [LPAR04]: (IF1(false, s(z0), s(z1)) -> MOD(if(gt(z0, z1), z0, s(z1)), s(z1)),IF1(false, s(z0), s(z1)) -> MOD(if(gt(z0, z1), z0, s(z1)), s(z1))) ---------------------------------------- (44) Obligation: Q DP problem: The TRS P consists of the following rules: MOD(s(x0), s(x1)) -> IF1(lt(x0, x1), s(x0), s(x1)) IF1(false, s(z0), s(z1)) -> MOD(if(gt(z0, z1), z0, s(z1)), s(z1)) The TRS R consists of the following rules: lt(0, s(x)) -> true lt(s(x), s(y)) -> lt(x, y) lt(x, 0) -> false minus(0, y) -> 0 minus(s(x), y) -> if(gt(s(x), y), x, y) gt(s(x), 0) -> true gt(s(x), s(y)) -> gt(x, y) if(true, x, y) -> s(minus(x, y)) if(false, x, y) -> 0 gt(0, y) -> false The set Q consists of the following terms: minus(0, x0) minus(s(x0), x1) if(true, x0, x1) if(false, x0, x1) gt(0, x0) gt(s(x0), 0) gt(s(x0), s(x1)) lt(x0, 0) lt(0, s(x0)) lt(s(x0), s(x1)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (45) Induction-Processor (SOUND) This DP could be deleted by the Induction-Processor: IF1(false_renamed, s(z0), s(z1)) -> MOD(if(gt(z0, z1), z0, s(z1)), s(z1)) This order was computed: Polynomial interpretation [POLO]: POL(0) = 0 POL(IF1(x_1, x_2, x_3)) = x_2 POL(MOD(x_1, x_2)) = x_1 POL(false_renamed) = 0 POL(gt(x_1, x_2)) = 0 POL(if(x_1, x_2, x_3)) = 1 + x_2 POL(lt(x_1, x_2)) = x_1 POL(minus(x_1, x_2)) = x_1 POL(s(x_1)) = 1 + x_1 POL(true_renamed) = 0 At least one of these decreasing rules is always used after the deleted DP: if(false_renamed, x5, y1) -> 0 The following formula is valid: z0:sort[a22],z1:sort[a22].if'(gt(z0, z1), z0, s(z1))=true The transformed set: if'(true_renamed, x4, y'') -> minus'(x4, y'') if'(false_renamed, x5, y1) -> true minus'(0, y3) -> false minus'(s(x6), y4) -> if'(gt(s(x6), y4), x6, y4) lt(0, s(x)) -> true_renamed lt(s(x'), s(y)) -> lt(x', y) lt(x'', 0) -> false_renamed gt(s(x2), 0) -> true_renamed gt(s(x3), s(y')) -> gt(x3, y') if(true_renamed, x4, y'') -> s(minus(x4, y'')) if(false_renamed, x5, y1) -> 0 gt(0, y2) -> false_renamed minus(0, y3) -> 0 minus(s(x6), y4) -> if(gt(s(x6), y4), x6, y4) equal_bool(true, false) -> false equal_bool(false, true) -> false equal_bool(true, true) -> true equal_bool(false, false) -> true and(true, x) -> x and(false, x) -> false or(true, x) -> true or(false, x) -> x not(false) -> true not(true) -> false isa_true(true) -> true isa_true(false) -> false isa_false(true) -> false isa_false(false) -> true equal_sort[a22](0, 0) -> true equal_sort[a22](0, s(v30)) -> false equal_sort[a22](s(v31), 0) -> false equal_sort[a22](s(v31), s(v32)) -> equal_sort[a22](v31, v32) equal_sort[a21](true_renamed, true_renamed) -> true equal_sort[a21](true_renamed, false_renamed) -> false equal_sort[a21](false_renamed, true_renamed) -> false equal_sort[a21](false_renamed, false_renamed) -> true equal_sort[a39](witness_sort[a39], witness_sort[a39]) -> true The proof given by the theorem prover: The following output was given by the internal theorem prover:proof of internal # AProVE Commit ID: 48fb2092695e11cc9f56e44b17a92a5f88ffb256 marcel 20180622 unpublished dirty Partial correctness of the following Program [x, v30, v31, v32, x5, y1, y'', x6, y3, y4, x', y, x'', x2, x3, y', y2] equal_bool(true, false) -> false equal_bool(false, true) -> false equal_bool(true, true) -> true equal_bool(false, false) -> true true and x -> x false and x -> false true or x -> true false or x -> x not(false) -> true not(true) -> false isa_true(true) -> true isa_true(false) -> false isa_false(true) -> false isa_false(false) -> true equal_sort[a22](0, 0) -> true equal_sort[a22](0, s(v30)) -> false equal_sort[a22](s(v31), 0) -> false equal_sort[a22](s(v31), s(v32)) -> equal_sort[a22](v31, v32) equal_sort[a21](true_renamed, true_renamed) -> true equal_sort[a21](true_renamed, false_renamed) -> false equal_sort[a21](false_renamed, true_renamed) -> false equal_sort[a21](false_renamed, false_renamed) -> true equal_sort[a39](witness_sort[a39], witness_sort[a39]) -> true if'(false_renamed, x5, y1) -> true if'(true_renamed, 0, y'') -> false if'(true_renamed, s(x6), y'') -> if'(gt(s(x6), y''), x6, y'') minus'(0, y3) -> false equal_sort[a21](gt(s(x6), y4), true_renamed) -> true | minus'(s(x6), y4) -> minus'(x6, y4) equal_sort[a21](gt(s(x6), y4), true_renamed) -> false | minus'(s(x6), y4) -> true lt(0, s(x)) -> true_renamed lt(s(x'), s(y)) -> lt(x', y) lt(x'', 0) -> false_renamed gt(s(x2), 0) -> true_renamed gt(s(x3), s(y')) -> gt(x3, y') gt(0, y2) -> false_renamed if(false_renamed, x5, y1) -> 0 if(true_renamed, 0, y'') -> s(0) if(true_renamed, s(x6), y'') -> s(if(gt(s(x6), y''), x6, y'')) minus(0, y3) -> 0 equal_sort[a21](gt(s(x6), y4), true_renamed) -> true | minus(s(x6), y4) -> s(minus(x6, y4)) equal_sort[a21](gt(s(x6), y4), true_renamed) -> false | minus(s(x6), y4) -> 0 using the following formula: z0:sort[a22],z1:sort[a22].if'(gt(z0, z1), z0, s(z1))=true could be successfully shown: (0) Formula (1) Induction by algorithm [EQUIVALENT, 0 ms] (2) AND (3) Formula (4) Symbolic evaluation [EQUIVALENT, 0 ms] (5) Formula (6) Induction by data structure [EQUIVALENT, 0 ms] (7) AND (8) Formula (9) Symbolic evaluation [EQUIVALENT, 0 ms] (10) YES (11) Formula (12) Symbolic evaluation under hypothesis [EQUIVALENT, 0 ms] (13) YES (14) Formula (15) Symbolic evaluation [EQUIVALENT, 0 ms] (16) YES (17) Formula (18) Symbolic evaluation [EQUIVALENT, 0 ms] (19) Formula (20) Hypothesis Lifting [EQUIVALENT, 0 ms] (21) Formula (22) Inverse Substitution [SOUND, 0 ms] (23) Formula (24) Inverse Substitution [SOUND, 0 ms] (25) Formula (26) Induction by algorithm [EQUIVALENT, 0 ms] (27) AND (28) Formula (29) Symbolic evaluation [EQUIVALENT, 0 ms] (30) YES (31) Formula (32) Symbolic evaluation [EQUIVALENT, 0 ms] (33) YES (34) Formula (35) Symbolic evaluation under hypothesis [EQUIVALENT, 0 ms] (36) YES ---------------------------------------- (0) Obligation: Formula: z0:sort[a22],z1:sort[a22].if'(gt(z0, z1), z0, s(z1))=true There are no hypotheses. ---------------------------------------- (1) Induction by algorithm (EQUIVALENT) Induction by algorithm gt(z0, z1) generates the following cases: 1. Base Case: Formula: x2:sort[a22].if'(gt(s(x2), 0), s(x2), s(0))=true There are no hypotheses. 2. Base Case: Formula: y2:sort[a22].if'(gt(0, y2), 0, s(y2))=true There are no hypotheses. 1. Step Case: Formula: x3:sort[a22],y':sort[a22].if'(gt(s(x3), s(y')), s(x3), s(s(y')))=true Hypotheses: x3:sort[a22],y':sort[a22].if'(gt(x3, y'), x3, s(y'))=true ---------------------------------------- (2) Complex Obligation (AND) ---------------------------------------- (3) Obligation: Formula: x2:sort[a22].if'(gt(s(x2), 0), s(x2), s(0))=true There are no hypotheses. ---------------------------------------- (4) Symbolic evaluation (EQUIVALENT) Could be shown by simple symbolic evaluation. ---------------------------------------- (5) Obligation: Formula: x2:sort[a22].if'(gt(x2, 0), x2, s(0))=true There are no hypotheses. ---------------------------------------- (6) Induction by data structure (EQUIVALENT) Induction by data structure sort[a22] generates the following cases: 1. Base Case: Formula: if'(gt(0, 0), 0, s(0))=true There are no hypotheses. 1. Step Case: Formula: n:sort[a22].if'(gt(s(n), 0), s(n), s(0))=true Hypotheses: n:sort[a22].if'(gt(n, 0), n, s(0))=true ---------------------------------------- (7) Complex Obligation (AND) ---------------------------------------- (8) Obligation: Formula: if'(gt(0, 0), 0, s(0))=true There are no hypotheses. ---------------------------------------- (9) Symbolic evaluation (EQUIVALENT) Could be reduced to the following new obligation by simple symbolic evaluation: True ---------------------------------------- (10) YES ---------------------------------------- (11) Obligation: Formula: n:sort[a22].if'(gt(s(n), 0), s(n), s(0))=true Hypotheses: n:sort[a22].if'(gt(n, 0), n, s(0))=true ---------------------------------------- (12) Symbolic evaluation under hypothesis (EQUIVALENT) Could be shown using symbolic evaluation under hypothesis, by using the following hypotheses: n:sort[a22].if'(gt(n, 0), n, s(0))=true ---------------------------------------- (13) YES ---------------------------------------- (14) Obligation: Formula: y2:sort[a22].if'(gt(0, y2), 0, s(y2))=true There are no hypotheses. ---------------------------------------- (15) Symbolic evaluation (EQUIVALENT) Could be reduced to the following new obligation by simple symbolic evaluation: True ---------------------------------------- (16) YES ---------------------------------------- (17) Obligation: Formula: x3:sort[a22],y':sort[a22].if'(gt(s(x3), s(y')), s(x3), s(s(y')))=true Hypotheses: x3:sort[a22],y':sort[a22].if'(gt(x3, y'), x3, s(y'))=true ---------------------------------------- (18) Symbolic evaluation (EQUIVALENT) Could be shown by simple symbolic evaluation. ---------------------------------------- (19) Obligation: Formula: x3:sort[a22],y':sort[a22].if'(gt(x3, y'), s(x3), s(s(y')))=true Hypotheses: x3:sort[a22],y':sort[a22].if'(gt(x3, y'), x3, s(y'))=true ---------------------------------------- (20) Hypothesis Lifting (EQUIVALENT) Formula could be generalised by hypothesis lifting to the following new obligation: Formula: x3:sort[a22],y':sort[a22].(if'(gt(x3, y'), x3, s(y'))=true->if'(gt(x3, y'), s(x3), s(s(y')))=true) There are no hypotheses. ---------------------------------------- (21) Obligation: Formula: x3:sort[a22],y':sort[a22].(if'(gt(x3, y'), x3, s(y'))=true->if'(gt(x3, y'), s(x3), s(s(y')))=true) There are no hypotheses. ---------------------------------------- (22) Inverse Substitution (SOUND) The formula could be generalised by inverse substitution to: n:sort[a21],x3:sort[a22],y':sort[a22].(if'(n, x3, s(y'))=true->if'(n, s(x3), s(s(y')))=true) Inverse substitution used: [gt(x3, y')/n] ---------------------------------------- (23) Obligation: Formula: n:sort[a21],x3:sort[a22],y':sort[a22].(if'(n, x3, s(y'))=true->if'(n, s(x3), s(s(y')))=true) There are no hypotheses. ---------------------------------------- (24) Inverse Substitution (SOUND) The formula could be generalised by inverse substitution to: n:sort[a21],x3:sort[a22],n':sort[a22].(if'(n, x3, n')=true->if'(n, s(x3), s(n'))=true) Inverse substitution used: [s(y')/n'] ---------------------------------------- (25) Obligation: Formula: n:sort[a21],x3:sort[a22],n':sort[a22].(if'(n, x3, n')=true->if'(n, s(x3), s(n'))=true) There are no hypotheses. ---------------------------------------- (26) Induction by algorithm (EQUIVALENT) Induction by algorithm if'(n, x3, n') generates the following cases: 1. Base Case: Formula: x5:sort[a22],y1:sort[a22].(if'(false_renamed, x5, y1)=true->if'(false_renamed, s(x5), s(y1))=true) There are no hypotheses. 2. Base Case: Formula: y'':sort[a22].(if'(true_renamed, 0, y'')=true->if'(true_renamed, s(0), s(y''))=true) There are no hypotheses. 1. Step Case: Formula: x6:sort[a22],y'':sort[a22].(if'(true_renamed, s(x6), y'')=true->if'(true_renamed, s(s(x6)), s(y''))=true) Hypotheses: x6:sort[a22],y'':sort[a22].(if'(gt(s(x6), y''), x6, y'')=true->if'(gt(s(x6), y''), s(x6), s(y''))=true) ---------------------------------------- (27) Complex Obligation (AND) ---------------------------------------- (28) Obligation: Formula: x5:sort[a22],y1:sort[a22].(if'(false_renamed, x5, y1)=true->if'(false_renamed, s(x5), s(y1))=true) There are no hypotheses. ---------------------------------------- (29) Symbolic evaluation (EQUIVALENT) Could be reduced to the following new obligation by simple symbolic evaluation: True ---------------------------------------- (30) YES ---------------------------------------- (31) Obligation: Formula: y'':sort[a22].(if'(true_renamed, 0, y'')=true->if'(true_renamed, s(0), s(y''))=true) There are no hypotheses. ---------------------------------------- (32) Symbolic evaluation (EQUIVALENT) Could be reduced to the following new obligation by simple symbolic evaluation: True ---------------------------------------- (33) YES ---------------------------------------- (34) Obligation: Formula: x6:sort[a22],y'':sort[a22].(if'(true_renamed, s(x6), y'')=true->if'(true_renamed, s(s(x6)), s(y''))=true) Hypotheses: x6:sort[a22],y'':sort[a22].(if'(gt(s(x6), y''), x6, y'')=true->if'(gt(s(x6), y''), s(x6), s(y''))=true) ---------------------------------------- (35) Symbolic evaluation under hypothesis (EQUIVALENT) Could be shown using symbolic evaluation under hypothesis, by using the following hypotheses: x6:sort[a22],y'':sort[a22].(if'(gt(s(x6), y''), x6, y'')=true->if'(gt(s(x6), y''), s(x6), s(y''))=true) ---------------------------------------- (36) YES ---------------------------------------- (46) Complex Obligation (AND) ---------------------------------------- (47) Obligation: Q DP problem: The TRS P consists of the following rules: MOD(s(x0), s(x1)) -> IF1(lt(x0, x1), s(x0), s(x1)) The TRS R consists of the following rules: lt(0, s(x)) -> true lt(s(x), s(y)) -> lt(x, y) lt(x, 0) -> false minus(0, y) -> 0 minus(s(x), y) -> if(gt(s(x), y), x, y) gt(s(x), 0) -> true gt(s(x), s(y)) -> gt(x, y) if(true, x, y) -> s(minus(x, y)) if(false, x, y) -> 0 gt(0, y) -> false The set Q consists of the following terms: minus(0, x0) minus(s(x0), x1) if(true, x0, x1) if(false, x0, x1) gt(0, x0) gt(s(x0), 0) gt(s(x0), s(x1)) lt(x0, 0) lt(0, s(x0)) lt(s(x0), s(x1)) 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 ---------------------------------------- (50) Obligation: Q restricted rewrite system: The TRS R consists of the following rules: if'(true_renamed, x4, y'') -> minus'(x4, y'') if'(false_renamed, x5, y1) -> true minus'(0, y3) -> false minus'(s(x6), y4) -> if'(gt(s(x6), y4), x6, y4) lt(0, s(x)) -> true_renamed lt(s(x'), s(y)) -> lt(x', y) lt(x'', 0) -> false_renamed gt(s(x2), 0) -> true_renamed gt(s(x3), s(y')) -> gt(x3, y') if(true_renamed, x4, y'') -> s(minus(x4, y'')) if(false_renamed, x5, y1) -> 0 gt(0, y2) -> false_renamed minus(0, y3) -> 0 minus(s(x6), y4) -> if(gt(s(x6), y4), x6, y4) equal_bool(true, false) -> false equal_bool(false, true) -> false equal_bool(true, true) -> true equal_bool(false, false) -> true and(true, x) -> x and(false, x) -> false or(true, x) -> true or(false, x) -> x not(false) -> true not(true) -> false isa_true(true) -> true isa_true(false) -> false isa_false(true) -> false isa_false(false) -> true equal_sort[a22](0, 0) -> true equal_sort[a22](0, s(v30)) -> false equal_sort[a22](s(v31), 0) -> false equal_sort[a22](s(v31), s(v32)) -> equal_sort[a22](v31, v32) equal_sort[a21](true_renamed, true_renamed) -> true equal_sort[a21](true_renamed, false_renamed) -> false equal_sort[a21](false_renamed, true_renamed) -> false equal_sort[a21](false_renamed, false_renamed) -> true equal_sort[a39](witness_sort[a39], witness_sort[a39]) -> true Q is empty. ---------------------------------------- (51) QTRSRRRProof (EQUIVALENT) Used ordering: Quasi precedence: [if'_3, minus'_2] > [true_renamed, gt_2] > true > false [if'_3, minus'_2] > [true_renamed, gt_2] > s_1 > false [if'_3, minus'_2] > [true_renamed, gt_2] > s_1 > lt_2 [false_renamed, 0, if_3, minus_2] > [true_renamed, gt_2] > true > false [false_renamed, 0, if_3, minus_2] > [true_renamed, gt_2] > s_1 > false [false_renamed, 0, if_3, minus_2] > [true_renamed, gt_2] > s_1 > lt_2 equal_bool_2 > true > false not_1 > true > false isa_false_1 > true > false equal_sort[a22]_2 > true > false equal_sort[a21]_2 > true > false equal_sort[a39]_2 > true > false witness_sort[a39] > true > false Status: if'_3: [2,3,1] true_renamed: multiset status minus'_2: [1,2] false_renamed: multiset status true: multiset status 0: multiset status false: multiset status s_1: [1] gt_2: multiset status lt_2: [1,2] if_3: [2,3,1] minus_2: [1,2] equal_bool_2: multiset status and_2: [2,1] or_2: [2,1] not_1: multiset status isa_true_1: multiset status isa_false_1: multiset status equal_sort[a22]_2: multiset status equal_sort[a21]_2: [1,2] equal_sort[a39]_2: multiset status witness_sort[a39]: multiset status With this ordering the following rules can be removed by the rule removal processor [LPAR04] because they are oriented strictly: if'(true_renamed, x4, y'') -> minus'(x4, y'') if'(false_renamed, x5, y1) -> true minus'(0, y3) -> false minus'(s(x6), y4) -> if'(gt(s(x6), y4), x6, y4) lt(0, s(x)) -> true_renamed lt(s(x'), s(y)) -> lt(x', y) lt(x'', 0) -> false_renamed gt(s(x2), 0) -> true_renamed gt(s(x3), s(y')) -> gt(x3, y') if(true_renamed, x4, y'') -> s(minus(x4, y'')) if(false_renamed, x5, y1) -> 0 gt(0, y2) -> false_renamed minus(0, y3) -> 0 minus(s(x6), y4) -> if(gt(s(x6), y4), x6, y4) equal_bool(true, false) -> false equal_bool(false, true) -> false equal_bool(true, true) -> true equal_bool(false, false) -> true and(true, x) -> x and(false, x) -> false or(true, x) -> true or(false, x) -> x not(false) -> true not(true) -> false isa_true(true) -> true isa_true(false) -> false isa_false(true) -> false isa_false(false) -> true equal_sort[a22](0, 0) -> true equal_sort[a22](0, s(v30)) -> false equal_sort[a22](s(v31), 0) -> false equal_sort[a22](s(v31), s(v32)) -> equal_sort[a22](v31, v32) equal_sort[a21](true_renamed, true_renamed) -> true equal_sort[a21](true_renamed, false_renamed) -> false equal_sort[a21](false_renamed, true_renamed) -> false equal_sort[a21](false_renamed, false_renamed) -> true equal_sort[a39](witness_sort[a39], witness_sort[a39]) -> true ---------------------------------------- (52) Obligation: Q restricted rewrite system: R is empty. Q is empty. ---------------------------------------- (53) RisEmptyProof (EQUIVALENT) The TRS R is empty. Hence, termination is trivially proven. ---------------------------------------- (54) YES