/export/starexec/sandbox/solver/bin/starexec_run_standard /export/starexec/sandbox/benchmark/theBenchmark.xml /export/starexec/sandbox/output/output_files -------------------------------------------------------------------------------- NO 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# AProVE Commit ID: 48fb2092695e11cc9f56e44b17a92a5f88ffb256 marcel 20180622 unpublished dirty Termination w.r.t. Q of the given QTRS could be disproven: (0) QTRS (1) DependencyPairsProof [EQUIVALENT, 3 ms] (2) QDP (3) DependencyGraphProof [EQUIVALENT, 0 ms] (4) AND (5) QDP (6) MNOCProof [EQUIVALENT, 0 ms] (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) MNOCProof [EQUIVALENT, 0 ms] (16) QDP (17) UsableRulesProof [EQUIVALENT, 0 ms] (18) QDP (19) QReductionProof [EQUIVALENT, 0 ms] (20) QDP (21) QDPSizeChangeProof [EQUIVALENT, 0 ms] (22) YES (23) QDP (24) MNOCProof [EQUIVALENT, 0 ms] (25) QDP (26) UsableRulesProof [EQUIVALENT, 0 ms] (27) QDP (28) QReductionProof [EQUIVALENT, 0 ms] (29) QDP (30) QDPSizeChangeProof [EQUIVALENT, 0 ms] (31) YES (32) QDP (33) MNOCProof [EQUIVALENT, 0 ms] (34) QDP (35) UsableRulesProof [EQUIVALENT, 0 ms] (36) QDP (37) QReductionProof [EQUIVALENT, 0 ms] (38) QDP (39) QDPSizeChangeProof [EQUIVALENT, 0 ms] (40) YES (41) QDP (42) MNOCProof [EQUIVALENT, 0 ms] (43) QDP (44) UsableRulesProof [EQUIVALENT, 0 ms] (45) QDP (46) QReductionProof [EQUIVALENT, 0 ms] (47) QDP (48) QDPSizeChangeProof [EQUIVALENT, 0 ms] (49) YES (50) QDP (51) MNOCProof [EQUIVALENT, 0 ms] (52) QDP (53) UsableRulesProof [EQUIVALENT, 0 ms] (54) QDP (55) QReductionProof [EQUIVALENT, 0 ms] (56) QDP (57) TransformationProof [EQUIVALENT, 0 ms] (58) QDP (59) TransformationProof [EQUIVALENT, 0 ms] (60) QDP (61) NonTerminationLoopProof [COMPLETE, 0 ms] (62) NO ---------------------------------------- (0) Obligation: Q restricted rewrite system: The TRS R consists of the following rules: terms(N) -> cons(recip(sqr(N)), terms(s(N))) sqr(0) -> 0 sqr(s(X)) -> s(add(sqr(X), dbl(X))) dbl(0) -> 0 dbl(s(X)) -> s(s(dbl(X))) add(0, X) -> X add(s(X), Y) -> s(add(X, Y)) first(0, X) -> nil first(s(X), cons(Y, Z)) -> cons(Y, first(X, Z)) half(0) -> 0 half(s(0)) -> 0 half(s(s(X))) -> s(half(X)) half(dbl(X)) -> X 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: TERMS(N) -> SQR(N) TERMS(N) -> TERMS(s(N)) SQR(s(X)) -> ADD(sqr(X), dbl(X)) SQR(s(X)) -> SQR(X) SQR(s(X)) -> DBL(X) DBL(s(X)) -> DBL(X) ADD(s(X), Y) -> ADD(X, Y) FIRST(s(X), cons(Y, Z)) -> FIRST(X, Z) HALF(s(s(X))) -> HALF(X) The TRS R consists of the following rules: terms(N) -> cons(recip(sqr(N)), terms(s(N))) sqr(0) -> 0 sqr(s(X)) -> s(add(sqr(X), dbl(X))) dbl(0) -> 0 dbl(s(X)) -> s(s(dbl(X))) add(0, X) -> X add(s(X), Y) -> s(add(X, Y)) first(0, X) -> nil first(s(X), cons(Y, Z)) -> cons(Y, first(X, Z)) half(0) -> 0 half(s(0)) -> 0 half(s(s(X))) -> s(half(X)) half(dbl(X)) -> X 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 6 SCCs with 3 less nodes. ---------------------------------------- (4) Complex Obligation (AND) ---------------------------------------- (5) Obligation: Q DP problem: The TRS P consists of the following rules: HALF(s(s(X))) -> HALF(X) The TRS R consists of the following rules: terms(N) -> cons(recip(sqr(N)), terms(s(N))) sqr(0) -> 0 sqr(s(X)) -> s(add(sqr(X), dbl(X))) dbl(0) -> 0 dbl(s(X)) -> s(s(dbl(X))) add(0, X) -> X add(s(X), Y) -> s(add(X, Y)) first(0, X) -> nil first(s(X), cons(Y, Z)) -> cons(Y, first(X, Z)) half(0) -> 0 half(s(0)) -> 0 half(s(s(X))) -> s(half(X)) half(dbl(X)) -> X Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (6) MNOCProof (EQUIVALENT) We use the modular non-overlap check [LPAR04] to enlarge Q to all left-hand sides of R. ---------------------------------------- (7) Obligation: Q DP problem: The TRS P consists of the following rules: HALF(s(s(X))) -> HALF(X) The TRS R consists of the following rules: terms(N) -> cons(recip(sqr(N)), terms(s(N))) sqr(0) -> 0 sqr(s(X)) -> s(add(sqr(X), dbl(X))) dbl(0) -> 0 dbl(s(X)) -> s(s(dbl(X))) add(0, X) -> X add(s(X), Y) -> s(add(X, Y)) first(0, X) -> nil first(s(X), cons(Y, Z)) -> cons(Y, first(X, Z)) half(0) -> 0 half(s(0)) -> 0 half(s(s(X))) -> s(half(X)) half(dbl(X)) -> X The set Q consists of the following terms: terms(x0) sqr(0) sqr(s(x0)) dbl(0) dbl(s(x0)) add(0, x0) add(s(x0), x1) first(0, x0) first(s(x0), cons(x1, x2)) half(0) half(s(0)) half(s(s(x0))) half(dbl(x0)) 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: HALF(s(s(X))) -> HALF(X) R is empty. The set Q consists of the following terms: terms(x0) sqr(0) sqr(s(x0)) dbl(0) dbl(s(x0)) add(0, x0) add(s(x0), x1) first(0, x0) first(s(x0), cons(x1, x2)) half(0) half(s(0)) half(s(s(x0))) half(dbl(x0)) 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]. terms(x0) sqr(0) sqr(s(x0)) dbl(0) dbl(s(x0)) add(0, x0) add(s(x0), x1) first(0, x0) first(s(x0), cons(x1, x2)) half(0) half(s(0)) half(s(s(x0))) half(dbl(x0)) ---------------------------------------- (11) Obligation: Q DP problem: The TRS P consists of the following rules: HALF(s(s(X))) -> HALF(X) 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: *HALF(s(s(X))) -> HALF(X) The graph contains the following edges 1 > 1 ---------------------------------------- (13) YES ---------------------------------------- (14) Obligation: Q DP problem: The TRS P consists of the following rules: FIRST(s(X), cons(Y, Z)) -> FIRST(X, Z) The TRS R consists of the following rules: terms(N) -> cons(recip(sqr(N)), terms(s(N))) sqr(0) -> 0 sqr(s(X)) -> s(add(sqr(X), dbl(X))) dbl(0) -> 0 dbl(s(X)) -> s(s(dbl(X))) add(0, X) -> X add(s(X), Y) -> s(add(X, Y)) first(0, X) -> nil first(s(X), cons(Y, Z)) -> cons(Y, first(X, Z)) half(0) -> 0 half(s(0)) -> 0 half(s(s(X))) -> s(half(X)) half(dbl(X)) -> X Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (15) MNOCProof (EQUIVALENT) We use the modular non-overlap check [LPAR04] to enlarge Q to all left-hand sides of R. ---------------------------------------- (16) Obligation: Q DP problem: The TRS P consists of the following rules: FIRST(s(X), cons(Y, Z)) -> FIRST(X, Z) The TRS R consists of the following rules: terms(N) -> cons(recip(sqr(N)), terms(s(N))) sqr(0) -> 0 sqr(s(X)) -> s(add(sqr(X), dbl(X))) dbl(0) -> 0 dbl(s(X)) -> s(s(dbl(X))) add(0, X) -> X add(s(X), Y) -> s(add(X, Y)) first(0, X) -> nil first(s(X), cons(Y, Z)) -> cons(Y, first(X, Z)) half(0) -> 0 half(s(0)) -> 0 half(s(s(X))) -> s(half(X)) half(dbl(X)) -> X The set Q consists of the following terms: terms(x0) sqr(0) sqr(s(x0)) dbl(0) dbl(s(x0)) add(0, x0) add(s(x0), x1) first(0, x0) first(s(x0), cons(x1, x2)) half(0) half(s(0)) half(s(s(x0))) half(dbl(x0)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (17) 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. ---------------------------------------- (18) Obligation: Q DP problem: The TRS P consists of the following rules: FIRST(s(X), cons(Y, Z)) -> FIRST(X, Z) R is empty. The set Q consists of the following terms: terms(x0) sqr(0) sqr(s(x0)) dbl(0) dbl(s(x0)) add(0, x0) add(s(x0), x1) first(0, x0) first(s(x0), cons(x1, x2)) half(0) half(s(0)) half(s(s(x0))) half(dbl(x0)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (19) 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]. terms(x0) sqr(0) sqr(s(x0)) dbl(0) dbl(s(x0)) add(0, x0) add(s(x0), x1) first(0, x0) first(s(x0), cons(x1, x2)) half(0) half(s(0)) half(s(s(x0))) half(dbl(x0)) ---------------------------------------- (20) Obligation: Q DP problem: The TRS P consists of the following rules: FIRST(s(X), cons(Y, Z)) -> FIRST(X, Z) R is empty. Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (21) 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: *FIRST(s(X), cons(Y, Z)) -> FIRST(X, Z) The graph contains the following edges 1 > 1, 2 > 2 ---------------------------------------- (22) YES ---------------------------------------- (23) Obligation: Q DP problem: The TRS P consists of the following rules: ADD(s(X), Y) -> ADD(X, Y) The TRS R consists of the following rules: terms(N) -> cons(recip(sqr(N)), terms(s(N))) sqr(0) -> 0 sqr(s(X)) -> s(add(sqr(X), dbl(X))) dbl(0) -> 0 dbl(s(X)) -> s(s(dbl(X))) add(0, X) -> X add(s(X), Y) -> s(add(X, Y)) first(0, X) -> nil first(s(X), cons(Y, Z)) -> cons(Y, first(X, Z)) half(0) -> 0 half(s(0)) -> 0 half(s(s(X))) -> s(half(X)) half(dbl(X)) -> X Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (24) MNOCProof (EQUIVALENT) We use the modular non-overlap check [LPAR04] to enlarge Q to all left-hand sides of R. ---------------------------------------- (25) Obligation: Q DP problem: The TRS P consists of the following rules: ADD(s(X), Y) -> ADD(X, Y) The TRS R consists of the following rules: terms(N) -> cons(recip(sqr(N)), terms(s(N))) sqr(0) -> 0 sqr(s(X)) -> s(add(sqr(X), dbl(X))) dbl(0) -> 0 dbl(s(X)) -> s(s(dbl(X))) add(0, X) -> X add(s(X), Y) -> s(add(X, Y)) first(0, X) -> nil first(s(X), cons(Y, Z)) -> cons(Y, first(X, Z)) half(0) -> 0 half(s(0)) -> 0 half(s(s(X))) -> s(half(X)) half(dbl(X)) -> X The set Q consists of the following terms: terms(x0) sqr(0) sqr(s(x0)) dbl(0) dbl(s(x0)) add(0, x0) add(s(x0), x1) first(0, x0) first(s(x0), cons(x1, x2)) half(0) half(s(0)) half(s(s(x0))) half(dbl(x0)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (26) 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. ---------------------------------------- (27) Obligation: Q DP problem: The TRS P consists of the following rules: ADD(s(X), Y) -> ADD(X, Y) R is empty. The set Q consists of the following terms: terms(x0) sqr(0) sqr(s(x0)) dbl(0) dbl(s(x0)) add(0, x0) add(s(x0), x1) first(0, x0) first(s(x0), cons(x1, x2)) half(0) half(s(0)) half(s(s(x0))) half(dbl(x0)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (28) 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]. terms(x0) sqr(0) sqr(s(x0)) dbl(0) dbl(s(x0)) add(0, x0) add(s(x0), x1) first(0, x0) first(s(x0), cons(x1, x2)) half(0) half(s(0)) half(s(s(x0))) half(dbl(x0)) ---------------------------------------- (29) Obligation: Q DP problem: The TRS P consists of the following rules: ADD(s(X), Y) -> ADD(X, Y) R is empty. Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (30) 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: *ADD(s(X), Y) -> ADD(X, Y) The graph contains the following edges 1 > 1, 2 >= 2 ---------------------------------------- (31) YES ---------------------------------------- (32) Obligation: Q DP problem: The TRS P consists of the following rules: DBL(s(X)) -> DBL(X) The TRS R consists of the following rules: terms(N) -> cons(recip(sqr(N)), terms(s(N))) sqr(0) -> 0 sqr(s(X)) -> s(add(sqr(X), dbl(X))) dbl(0) -> 0 dbl(s(X)) -> s(s(dbl(X))) add(0, X) -> X add(s(X), Y) -> s(add(X, Y)) first(0, X) -> nil first(s(X), cons(Y, Z)) -> cons(Y, first(X, Z)) half(0) -> 0 half(s(0)) -> 0 half(s(s(X))) -> s(half(X)) half(dbl(X)) -> X 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: DBL(s(X)) -> DBL(X) The TRS R consists of the following rules: terms(N) -> cons(recip(sqr(N)), terms(s(N))) sqr(0) -> 0 sqr(s(X)) -> s(add(sqr(X), dbl(X))) dbl(0) -> 0 dbl(s(X)) -> s(s(dbl(X))) add(0, X) -> X add(s(X), Y) -> s(add(X, Y)) first(0, X) -> nil first(s(X), cons(Y, Z)) -> cons(Y, first(X, Z)) half(0) -> 0 half(s(0)) -> 0 half(s(s(X))) -> s(half(X)) half(dbl(X)) -> X The set Q consists of the following terms: terms(x0) sqr(0) sqr(s(x0)) dbl(0) dbl(s(x0)) add(0, x0) add(s(x0), x1) first(0, x0) first(s(x0), cons(x1, x2)) half(0) half(s(0)) half(s(s(x0))) half(dbl(x0)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (35) 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. ---------------------------------------- (36) Obligation: Q DP problem: The TRS P consists of the following rules: DBL(s(X)) -> DBL(X) R is empty. The set Q consists of the following terms: terms(x0) sqr(0) sqr(s(x0)) dbl(0) dbl(s(x0)) add(0, x0) add(s(x0), x1) first(0, x0) first(s(x0), cons(x1, x2)) half(0) half(s(0)) half(s(s(x0))) half(dbl(x0)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (37) 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]. terms(x0) sqr(0) sqr(s(x0)) dbl(0) dbl(s(x0)) add(0, x0) add(s(x0), x1) first(0, x0) first(s(x0), cons(x1, x2)) half(0) half(s(0)) half(s(s(x0))) half(dbl(x0)) ---------------------------------------- (38) Obligation: Q DP problem: The TRS P consists of the following rules: DBL(s(X)) -> DBL(X) R is empty. Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (39) 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: *DBL(s(X)) -> DBL(X) The graph contains the following edges 1 > 1 ---------------------------------------- (40) YES ---------------------------------------- (41) Obligation: Q DP problem: The TRS P consists of the following rules: SQR(s(X)) -> SQR(X) The TRS R consists of the following rules: terms(N) -> cons(recip(sqr(N)), terms(s(N))) sqr(0) -> 0 sqr(s(X)) -> s(add(sqr(X), dbl(X))) dbl(0) -> 0 dbl(s(X)) -> s(s(dbl(X))) add(0, X) -> X add(s(X), Y) -> s(add(X, Y)) first(0, X) -> nil first(s(X), cons(Y, Z)) -> cons(Y, first(X, Z)) half(0) -> 0 half(s(0)) -> 0 half(s(s(X))) -> s(half(X)) half(dbl(X)) -> X Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (42) MNOCProof (EQUIVALENT) We use the modular non-overlap check [LPAR04] to enlarge Q to all left-hand sides of R. ---------------------------------------- (43) Obligation: Q DP problem: The TRS P consists of the following rules: SQR(s(X)) -> SQR(X) The TRS R consists of the following rules: terms(N) -> cons(recip(sqr(N)), terms(s(N))) sqr(0) -> 0 sqr(s(X)) -> s(add(sqr(X), dbl(X))) dbl(0) -> 0 dbl(s(X)) -> s(s(dbl(X))) add(0, X) -> X add(s(X), Y) -> s(add(X, Y)) first(0, X) -> nil first(s(X), cons(Y, Z)) -> cons(Y, first(X, Z)) half(0) -> 0 half(s(0)) -> 0 half(s(s(X))) -> s(half(X)) half(dbl(X)) -> X The set Q consists of the following terms: terms(x0) sqr(0) sqr(s(x0)) dbl(0) dbl(s(x0)) add(0, x0) add(s(x0), x1) first(0, x0) first(s(x0), cons(x1, x2)) half(0) half(s(0)) half(s(s(x0))) half(dbl(x0)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (44) 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. ---------------------------------------- (45) Obligation: Q DP problem: The TRS P consists of the following rules: SQR(s(X)) -> SQR(X) R is empty. The set Q consists of the following terms: terms(x0) sqr(0) sqr(s(x0)) dbl(0) dbl(s(x0)) add(0, x0) add(s(x0), x1) first(0, x0) first(s(x0), cons(x1, x2)) half(0) half(s(0)) half(s(s(x0))) half(dbl(x0)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (46) 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]. terms(x0) sqr(0) sqr(s(x0)) dbl(0) dbl(s(x0)) add(0, x0) add(s(x0), x1) first(0, x0) first(s(x0), cons(x1, x2)) half(0) half(s(0)) half(s(s(x0))) half(dbl(x0)) ---------------------------------------- (47) Obligation: Q DP problem: The TRS P consists of the following rules: SQR(s(X)) -> SQR(X) R is empty. Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (48) 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: *SQR(s(X)) -> SQR(X) The graph contains the following edges 1 > 1 ---------------------------------------- (49) YES ---------------------------------------- (50) Obligation: Q DP problem: The TRS P consists of the following rules: TERMS(N) -> TERMS(s(N)) The TRS R consists of the following rules: terms(N) -> cons(recip(sqr(N)), terms(s(N))) sqr(0) -> 0 sqr(s(X)) -> s(add(sqr(X), dbl(X))) dbl(0) -> 0 dbl(s(X)) -> s(s(dbl(X))) add(0, X) -> X add(s(X), Y) -> s(add(X, Y)) first(0, X) -> nil first(s(X), cons(Y, Z)) -> cons(Y, first(X, Z)) half(0) -> 0 half(s(0)) -> 0 half(s(s(X))) -> s(half(X)) half(dbl(X)) -> X Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (51) MNOCProof (EQUIVALENT) We use the modular non-overlap check [LPAR04] to enlarge Q to all left-hand sides of R. ---------------------------------------- (52) Obligation: Q DP problem: The TRS P consists of the following rules: TERMS(N) -> TERMS(s(N)) The TRS R consists of the following rules: terms(N) -> cons(recip(sqr(N)), terms(s(N))) sqr(0) -> 0 sqr(s(X)) -> s(add(sqr(X), dbl(X))) dbl(0) -> 0 dbl(s(X)) -> s(s(dbl(X))) add(0, X) -> X add(s(X), Y) -> s(add(X, Y)) first(0, X) -> nil first(s(X), cons(Y, Z)) -> cons(Y, first(X, Z)) half(0) -> 0 half(s(0)) -> 0 half(s(s(X))) -> s(half(X)) half(dbl(X)) -> X The set Q consists of the following terms: terms(x0) sqr(0) sqr(s(x0)) dbl(0) dbl(s(x0)) add(0, x0) add(s(x0), x1) first(0, x0) first(s(x0), cons(x1, x2)) half(0) half(s(0)) half(s(s(x0))) half(dbl(x0)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (53) 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. ---------------------------------------- (54) Obligation: Q DP problem: The TRS P consists of the following rules: TERMS(N) -> TERMS(s(N)) R is empty. The set Q consists of the following terms: terms(x0) sqr(0) sqr(s(x0)) dbl(0) dbl(s(x0)) add(0, x0) add(s(x0), x1) first(0, x0) first(s(x0), cons(x1, x2)) half(0) half(s(0)) half(s(s(x0))) half(dbl(x0)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (55) 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]. terms(x0) sqr(0) sqr(s(x0)) dbl(0) dbl(s(x0)) add(0, x0) add(s(x0), x1) first(0, x0) first(s(x0), cons(x1, x2)) half(0) half(s(0)) half(s(s(x0))) half(dbl(x0)) ---------------------------------------- (56) Obligation: Q DP problem: The TRS P consists of the following rules: TERMS(N) -> TERMS(s(N)) R is empty. Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (57) TransformationProof (EQUIVALENT) By instantiating [LPAR04] the rule TERMS(N) -> TERMS(s(N)) we obtained the following new rules [LPAR04]: (TERMS(s(z0)) -> TERMS(s(s(z0))),TERMS(s(z0)) -> TERMS(s(s(z0)))) ---------------------------------------- (58) Obligation: Q DP problem: The TRS P consists of the following rules: TERMS(s(z0)) -> TERMS(s(s(z0))) R is empty. Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (59) TransformationProof (EQUIVALENT) By instantiating [LPAR04] the rule TERMS(s(z0)) -> TERMS(s(s(z0))) we obtained the following new rules [LPAR04]: (TERMS(s(s(z0))) -> TERMS(s(s(s(z0)))),TERMS(s(s(z0))) -> TERMS(s(s(s(z0))))) ---------------------------------------- (60) Obligation: Q DP problem: The TRS P consists of the following rules: TERMS(s(s(z0))) -> TERMS(s(s(s(z0)))) R is empty. Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (61) NonTerminationLoopProof (COMPLETE) We used the non-termination processor [FROCOS05] to show that the DP problem is infinite. Found a loop by semiunifying a rule from P directly. s = TERMS(s(s(z0))) evaluates to t =TERMS(s(s(s(z0)))) Thus s starts an infinite chain as s semiunifies with t with the following substitutions: * Matcher: [z0 / s(z0)] * Semiunifier: [ ] -------------------------------------------------------------------------------- Rewriting sequence The DP semiunifies directly so there is only one rewrite step from TERMS(s(s(z0))) to TERMS(s(s(s(z0)))). ---------------------------------------- (62) NO