/export/starexec/sandbox/solver/bin/starexec_run_standard /export/starexec/sandbox/benchmark/theBenchmark.xml /export/starexec/sandbox/output/output_files -------------------------------------------------------------------------------- MAYBE proof of /export/starexec/sandbox/benchmark/theBenchmark.xml # AProVE Commit ID: 48fb2092695e11cc9f56e44b17a92a5f88ffb256 marcel 20180622 unpublished dirty Outermost Termination of the given OTRS could not be shown: (0) OTRS (1) Trivial-Transformation [SOUND, 0 ms] (2) QTRS (3) QTRSRRRProof [EQUIVALENT, 62 ms] (4) QTRS (5) AAECC Innermost [EQUIVALENT, 0 ms] (6) QTRS (7) DependencyPairsProof [EQUIVALENT, 0 ms] (8) QDP (9) DependencyGraphProof [EQUIVALENT, 0 ms] (10) QDP (11) UsableRulesProof [EQUIVALENT, 0 ms] (12) QDP (13) QReductionProof [EQUIVALENT, 0 ms] (14) QDP (15) TransformationProof [EQUIVALENT, 0 ms] (16) QDP (17) UsableRulesProof [EQUIVALENT, 0 ms] (18) QDP (19) QReductionProof [EQUIVALENT, 0 ms] (20) QDP (21) TransformationProof [EQUIVALENT, 0 ms] (22) QDP (23) UsableRulesProof [EQUIVALENT, 0 ms] (24) QDP (25) QReductionProof [EQUIVALENT, 0 ms] (26) QDP (27) TransformationProof [EQUIVALENT, 0 ms] (28) QDP (29) NonTerminationLoopProof [COMPLETE, 0 ms] (30) NO (31) Thiemann-SpecialC-Transformation [EQUIVALENT, 0 ms] (32) QTRS (33) QTRSRRRProof [EQUIVALENT, 36 ms] (34) QTRS (35) DependencyPairsProof [EQUIVALENT, 0 ms] (36) QDP (37) DependencyGraphProof [EQUIVALENT, 0 ms] (38) AND (39) QDP (40) UsableRulesProof [EQUIVALENT, 0 ms] (41) QDP (42) QReductionProof [EQUIVALENT, 0 ms] (43) QDP (44) MRRProof [EQUIVALENT, 0 ms] (45) QDP (46) PisEmptyProof [EQUIVALENT, 0 ms] (47) YES (48) QDP (49) UsableRulesProof [EQUIVALENT, 0 ms] (50) QDP (51) QReductionProof [EQUIVALENT, 0 ms] (52) QDP (53) TransformationProof [SOUND, 0 ms] (54) QDP (55) DependencyGraphProof [EQUIVALENT, 0 ms] (56) QDP (57) UsableRulesProof [EQUIVALENT, 0 ms] (58) QDP (59) QReductionProof [EQUIVALENT, 0 ms] (60) QDP ---------------------------------------- (0) Obligation: Term rewrite system R: The TRS R consists of the following rules: f(x, x) -> f(0, 1) 0 -> 2 1 -> 2 f(x, 2) -> 2 f(2, x) -> 2 Outermost Strategy. ---------------------------------------- (1) Trivial-Transformation (SOUND) We applied the Trivial transformation to transform the outermost TRS to a standard TRS. ---------------------------------------- (2) Obligation: Q restricted rewrite system: The TRS R consists of the following rules: f(x, x) -> f(0, 1) 0 -> 2 1 -> 2 f(x, 2) -> 2 f(2, x) -> 2 Q is empty. ---------------------------------------- (3) QTRSRRRProof (EQUIVALENT) Used ordering: Polynomial interpretation [POLO]: POL(0) = 0 POL(1) = 0 POL(2) = 0 POL(f(x_1, x_2)) = 1 + x_1 + x_2 With this ordering the following rules can be removed by the rule removal processor [LPAR04] because they are oriented strictly: f(x, 2) -> 2 f(2, x) -> 2 ---------------------------------------- (4) Obligation: Q restricted rewrite system: The TRS R consists of the following rules: f(x, x) -> f(0, 1) 0 -> 2 1 -> 2 Q is empty. ---------------------------------------- (5) AAECC Innermost (EQUIVALENT) We have applied [NOC,AAECCNOC] to switch to innermost. The TRS R 1 is 0 -> 2 1 -> 2 The TRS R 2 is f(x, x) -> f(0, 1) The signature Sigma is {f_2} ---------------------------------------- (6) Obligation: Q restricted rewrite system: The TRS R consists of the following rules: f(x, x) -> f(0, 1) 0 -> 2 1 -> 2 The set Q consists of the following terms: f(x0, x0) 0 1 ---------------------------------------- (7) DependencyPairsProof (EQUIVALENT) Using Dependency Pairs [AG00,LPAR04] we result in the following initial DP problem. ---------------------------------------- (8) Obligation: Q DP problem: The TRS P consists of the following rules: F(x, x) -> F(0, 1) F(x, x) -> 0^1 F(x, x) -> 1^1 The TRS R consists of the following rules: f(x, x) -> f(0, 1) 0 -> 2 1 -> 2 The set Q consists of the following terms: f(x0, x0) 0 1 We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (9) DependencyGraphProof (EQUIVALENT) The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 1 SCC with 2 less nodes. ---------------------------------------- (10) Obligation: Q DP problem: The TRS P consists of the following rules: F(x, x) -> F(0, 1) The TRS R consists of the following rules: f(x, x) -> f(0, 1) 0 -> 2 1 -> 2 The set Q consists of the following terms: f(x0, x0) 0 1 We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (11) 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. ---------------------------------------- (12) Obligation: Q DP problem: The TRS P consists of the following rules: F(x, x) -> F(0, 1) The TRS R consists of the following rules: 0 -> 2 1 -> 2 The set Q consists of the following terms: f(x0, x0) 0 1 We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (13) 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]. f(x0, x0) ---------------------------------------- (14) Obligation: Q DP problem: The TRS P consists of the following rules: F(x, x) -> F(0, 1) The TRS R consists of the following rules: 0 -> 2 1 -> 2 The set Q consists of the following terms: 0 1 We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (15) TransformationProof (EQUIVALENT) By rewriting [LPAR04] the rule F(x, x) -> F(0, 1) at position [0] we obtained the following new rules [LPAR04]: (F(x, x) -> F(2, 1),F(x, x) -> F(2, 1)) ---------------------------------------- (16) Obligation: Q DP problem: The TRS P consists of the following rules: F(x, x) -> F(2, 1) The TRS R consists of the following rules: 0 -> 2 1 -> 2 The set Q consists of the following terms: 0 1 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: F(x, x) -> F(2, 1) The TRS R consists of the following rules: 1 -> 2 The set Q consists of the following terms: 0 1 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]. 0 ---------------------------------------- (20) Obligation: Q DP problem: The TRS P consists of the following rules: F(x, x) -> F(2, 1) The TRS R consists of the following rules: 1 -> 2 The set Q consists of the following terms: 1 We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (21) TransformationProof (EQUIVALENT) By rewriting [LPAR04] the rule F(x, x) -> F(2, 1) at position [1] we obtained the following new rules [LPAR04]: (F(x, x) -> F(2, 2),F(x, x) -> F(2, 2)) ---------------------------------------- (22) Obligation: Q DP problem: The TRS P consists of the following rules: F(x, x) -> F(2, 2) The TRS R consists of the following rules: 1 -> 2 The set Q consists of the following terms: 1 We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (23) 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. ---------------------------------------- (24) Obligation: Q DP problem: The TRS P consists of the following rules: F(x, x) -> F(2, 2) R is empty. The set Q consists of the following terms: 1 We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (25) 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]. 1 ---------------------------------------- (26) Obligation: Q DP problem: The TRS P consists of the following rules: F(x, x) -> F(2, 2) R is empty. Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (27) TransformationProof (EQUIVALENT) By instantiating [LPAR04] the rule F(x, x) -> F(2, 2) we obtained the following new rules [LPAR04]: (F(2, 2) -> F(2, 2),F(2, 2) -> F(2, 2)) ---------------------------------------- (28) Obligation: Q DP problem: The TRS P consists of the following rules: F(2, 2) -> F(2, 2) R is empty. Q is empty. We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (29) 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 = F(2, 2) evaluates to t =F(2, 2) Thus s starts an infinite chain as s semiunifies with t with the following substitutions: * Matcher: [ ] * Semiunifier: [ ] -------------------------------------------------------------------------------- Rewriting sequence The DP semiunifies directly so there is only one rewrite step from F(2, 2) to F(2, 2). ---------------------------------------- (30) NO ---------------------------------------- (31) Thiemann-SpecialC-Transformation (EQUIVALENT) We applied the Thiemann-SpecialC transformation to transform the outermost TRS to an innermost TRS. ---------------------------------------- (32) Obligation: Q restricted rewrite system: The TRS R consists of the following rules: top(go_up(x)) -> top(reduce(x)) reduce(f(x_1, x_2)) -> check_f(redex_f(x_1, x_2)) redex_f(x, x) -> result_f(f(0, 1)) reduce(0) -> go_up(2) reduce(1) -> go_up(2) redex_f(x, 2) -> result_f(2) redex_f(2, x) -> result_f(2) check_f(result_f(x)) -> go_up(x) check_f(redex_f(x_1, x_2)) -> in_f_1(reduce(x_1), x_2) check_f(redex_f(x_1, x_2)) -> in_f_2(x_1, reduce(x_2)) in_f_1(go_up(x_1), x_2) -> go_up(f(x_1, x_2)) in_f_2(x_1, go_up(x_2)) -> go_up(f(x_1, x_2)) The set Q consists of the following terms: top(go_up(x0)) reduce(f(x0, x1)) redex_f(x0, x0) reduce(0) reduce(1) redex_f(x0, 2) redex_f(2, x0) check_f(result_f(x0)) check_f(redex_f(x0, x1)) in_f_1(go_up(x0), x1) in_f_2(x0, go_up(x1)) ---------------------------------------- (33) QTRSRRRProof (EQUIVALENT) Used ordering: Polynomial interpretation [POLO]: POL(0) = 0 POL(1) = 0 POL(2) = 0 POL(check_f(x_1)) = x_1 POL(f(x_1, x_2)) = 1 + x_1 + x_2 POL(go_up(x_1)) = 2*x_1 POL(in_f_1(x_1, x_2)) = 2 + x_1 + 2*x_2 POL(in_f_2(x_1, x_2)) = 2 + 2*x_1 + x_2 POL(redex_f(x_1, x_2)) = 2 + 2*x_1 + 2*x_2 POL(reduce(x_1)) = 2*x_1 POL(result_f(x_1)) = 2*x_1 POL(top(x_1)) = x_1 With this ordering the following rules can be removed by the rule removal processor [LPAR04] because they are oriented strictly: redex_f(x, 2) -> result_f(2) redex_f(2, x) -> result_f(2) ---------------------------------------- (34) Obligation: Q restricted rewrite system: The TRS R consists of the following rules: top(go_up(x)) -> top(reduce(x)) reduce(f(x_1, x_2)) -> check_f(redex_f(x_1, x_2)) redex_f(x, x) -> result_f(f(0, 1)) reduce(0) -> go_up(2) reduce(1) -> go_up(2) check_f(result_f(x)) -> go_up(x) check_f(redex_f(x_1, x_2)) -> in_f_1(reduce(x_1), x_2) check_f(redex_f(x_1, x_2)) -> in_f_2(x_1, reduce(x_2)) in_f_1(go_up(x_1), x_2) -> go_up(f(x_1, x_2)) in_f_2(x_1, go_up(x_2)) -> go_up(f(x_1, x_2)) The set Q consists of the following terms: top(go_up(x0)) reduce(f(x0, x1)) redex_f(x0, x0) reduce(0) reduce(1) redex_f(x0, 2) redex_f(2, x0) check_f(result_f(x0)) check_f(redex_f(x0, x1)) in_f_1(go_up(x0), x1) in_f_2(x0, go_up(x1)) ---------------------------------------- (35) DependencyPairsProof (EQUIVALENT) Using Dependency Pairs [AG00,LPAR04] we result in the following initial DP problem. ---------------------------------------- (36) Obligation: Q DP problem: The TRS P consists of the following rules: TOP(go_up(x)) -> TOP(reduce(x)) TOP(go_up(x)) -> REDUCE(x) REDUCE(f(x_1, x_2)) -> CHECK_F(redex_f(x_1, x_2)) REDUCE(f(x_1, x_2)) -> REDEX_F(x_1, x_2) CHECK_F(redex_f(x_1, x_2)) -> IN_F_1(reduce(x_1), x_2) CHECK_F(redex_f(x_1, x_2)) -> REDUCE(x_1) CHECK_F(redex_f(x_1, x_2)) -> IN_F_2(x_1, reduce(x_2)) CHECK_F(redex_f(x_1, x_2)) -> REDUCE(x_2) The TRS R consists of the following rules: top(go_up(x)) -> top(reduce(x)) reduce(f(x_1, x_2)) -> check_f(redex_f(x_1, x_2)) redex_f(x, x) -> result_f(f(0, 1)) reduce(0) -> go_up(2) reduce(1) -> go_up(2) check_f(result_f(x)) -> go_up(x) check_f(redex_f(x_1, x_2)) -> in_f_1(reduce(x_1), x_2) check_f(redex_f(x_1, x_2)) -> in_f_2(x_1, reduce(x_2)) in_f_1(go_up(x_1), x_2) -> go_up(f(x_1, x_2)) in_f_2(x_1, go_up(x_2)) -> go_up(f(x_1, x_2)) The set Q consists of the following terms: top(go_up(x0)) reduce(f(x0, x1)) redex_f(x0, x0) reduce(0) reduce(1) redex_f(x0, 2) redex_f(2, x0) check_f(result_f(x0)) check_f(redex_f(x0, x1)) in_f_1(go_up(x0), x1) in_f_2(x0, go_up(x1)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (37) DependencyGraphProof (EQUIVALENT) The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 2 SCCs with 4 less nodes. ---------------------------------------- (38) Complex Obligation (AND) ---------------------------------------- (39) Obligation: Q DP problem: The TRS P consists of the following rules: CHECK_F(redex_f(x_1, x_2)) -> REDUCE(x_1) REDUCE(f(x_1, x_2)) -> CHECK_F(redex_f(x_1, x_2)) CHECK_F(redex_f(x_1, x_2)) -> REDUCE(x_2) The TRS R consists of the following rules: top(go_up(x)) -> top(reduce(x)) reduce(f(x_1, x_2)) -> check_f(redex_f(x_1, x_2)) redex_f(x, x) -> result_f(f(0, 1)) reduce(0) -> go_up(2) reduce(1) -> go_up(2) check_f(result_f(x)) -> go_up(x) check_f(redex_f(x_1, x_2)) -> in_f_1(reduce(x_1), x_2) check_f(redex_f(x_1, x_2)) -> in_f_2(x_1, reduce(x_2)) in_f_1(go_up(x_1), x_2) -> go_up(f(x_1, x_2)) in_f_2(x_1, go_up(x_2)) -> go_up(f(x_1, x_2)) The set Q consists of the following terms: top(go_up(x0)) reduce(f(x0, x1)) redex_f(x0, x0) reduce(0) reduce(1) redex_f(x0, 2) redex_f(2, x0) check_f(result_f(x0)) check_f(redex_f(x0, x1)) in_f_1(go_up(x0), x1) in_f_2(x0, go_up(x1)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (40) 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. ---------------------------------------- (41) Obligation: Q DP problem: The TRS P consists of the following rules: CHECK_F(redex_f(x_1, x_2)) -> REDUCE(x_1) REDUCE(f(x_1, x_2)) -> CHECK_F(redex_f(x_1, x_2)) CHECK_F(redex_f(x_1, x_2)) -> REDUCE(x_2) The TRS R consists of the following rules: redex_f(x, x) -> result_f(f(0, 1)) The set Q consists of the following terms: top(go_up(x0)) reduce(f(x0, x1)) redex_f(x0, x0) reduce(0) reduce(1) redex_f(x0, 2) redex_f(2, x0) check_f(result_f(x0)) check_f(redex_f(x0, x1)) in_f_1(go_up(x0), x1) in_f_2(x0, go_up(x1)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (42) 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]. top(go_up(x0)) reduce(f(x0, x1)) reduce(0) reduce(1) check_f(result_f(x0)) check_f(redex_f(x0, x1)) in_f_1(go_up(x0), x1) in_f_2(x0, go_up(x1)) ---------------------------------------- (43) Obligation: Q DP problem: The TRS P consists of the following rules: CHECK_F(redex_f(x_1, x_2)) -> REDUCE(x_1) REDUCE(f(x_1, x_2)) -> CHECK_F(redex_f(x_1, x_2)) CHECK_F(redex_f(x_1, x_2)) -> REDUCE(x_2) The TRS R consists of the following rules: redex_f(x, x) -> result_f(f(0, 1)) The set Q consists of the following terms: redex_f(x0, x0) redex_f(x0, 2) redex_f(2, x0) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (44) MRRProof (EQUIVALENT) By using the rule removal processor [LPAR04] with the following ordering, at least one Dependency Pair or term rewrite system rule of this QDP problem can be strictly oriented. Strictly oriented dependency pairs: CHECK_F(redex_f(x_1, x_2)) -> REDUCE(x_1) REDUCE(f(x_1, x_2)) -> CHECK_F(redex_f(x_1, x_2)) CHECK_F(redex_f(x_1, x_2)) -> REDUCE(x_2) Used ordering: Polynomial interpretation [POLO]: POL(0) = 0 POL(1) = 0 POL(CHECK_F(x_1)) = 1 + 2*x_1 POL(REDUCE(x_1)) = 2 + 2*x_1 POL(f(x_1, x_2)) = 1 + x_1 + 2*x_2 POL(redex_f(x_1, x_2)) = 1 + x_1 + x_2 POL(result_f(x_1)) = x_1 ---------------------------------------- (45) Obligation: Q DP problem: P is empty. The TRS R consists of the following rules: redex_f(x, x) -> result_f(f(0, 1)) The set Q consists of the following terms: redex_f(x0, x0) redex_f(x0, 2) redex_f(2, x0) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (46) PisEmptyProof (EQUIVALENT) The TRS P is empty. Hence, there is no (P,Q,R) chain. ---------------------------------------- (47) YES ---------------------------------------- (48) Obligation: Q DP problem: The TRS P consists of the following rules: TOP(go_up(x)) -> TOP(reduce(x)) The TRS R consists of the following rules: top(go_up(x)) -> top(reduce(x)) reduce(f(x_1, x_2)) -> check_f(redex_f(x_1, x_2)) redex_f(x, x) -> result_f(f(0, 1)) reduce(0) -> go_up(2) reduce(1) -> go_up(2) check_f(result_f(x)) -> go_up(x) check_f(redex_f(x_1, x_2)) -> in_f_1(reduce(x_1), x_2) check_f(redex_f(x_1, x_2)) -> in_f_2(x_1, reduce(x_2)) in_f_1(go_up(x_1), x_2) -> go_up(f(x_1, x_2)) in_f_2(x_1, go_up(x_2)) -> go_up(f(x_1, x_2)) The set Q consists of the following terms: top(go_up(x0)) reduce(f(x0, x1)) redex_f(x0, x0) reduce(0) reduce(1) redex_f(x0, 2) redex_f(2, x0) check_f(result_f(x0)) check_f(redex_f(x0, x1)) in_f_1(go_up(x0), x1) in_f_2(x0, go_up(x1)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (49) 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. ---------------------------------------- (50) Obligation: Q DP problem: The TRS P consists of the following rules: TOP(go_up(x)) -> TOP(reduce(x)) The TRS R consists of the following rules: reduce(f(x_1, x_2)) -> check_f(redex_f(x_1, x_2)) reduce(0) -> go_up(2) reduce(1) -> go_up(2) redex_f(x, x) -> result_f(f(0, 1)) check_f(result_f(x)) -> go_up(x) check_f(redex_f(x_1, x_2)) -> in_f_1(reduce(x_1), x_2) check_f(redex_f(x_1, x_2)) -> in_f_2(x_1, reduce(x_2)) in_f_2(x_1, go_up(x_2)) -> go_up(f(x_1, x_2)) in_f_1(go_up(x_1), x_2) -> go_up(f(x_1, x_2)) The set Q consists of the following terms: top(go_up(x0)) reduce(f(x0, x1)) redex_f(x0, x0) reduce(0) reduce(1) redex_f(x0, 2) redex_f(2, x0) check_f(result_f(x0)) check_f(redex_f(x0, x1)) in_f_1(go_up(x0), x1) in_f_2(x0, go_up(x1)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (51) 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]. top(go_up(x0)) ---------------------------------------- (52) Obligation: Q DP problem: The TRS P consists of the following rules: TOP(go_up(x)) -> TOP(reduce(x)) The TRS R consists of the following rules: reduce(f(x_1, x_2)) -> check_f(redex_f(x_1, x_2)) reduce(0) -> go_up(2) reduce(1) -> go_up(2) redex_f(x, x) -> result_f(f(0, 1)) check_f(result_f(x)) -> go_up(x) check_f(redex_f(x_1, x_2)) -> in_f_1(reduce(x_1), x_2) check_f(redex_f(x_1, x_2)) -> in_f_2(x_1, reduce(x_2)) in_f_2(x_1, go_up(x_2)) -> go_up(f(x_1, x_2)) in_f_1(go_up(x_1), x_2) -> go_up(f(x_1, x_2)) The set Q consists of the following terms: reduce(f(x0, x1)) redex_f(x0, x0) reduce(0) reduce(1) redex_f(x0, 2) redex_f(2, x0) check_f(result_f(x0)) check_f(redex_f(x0, x1)) in_f_1(go_up(x0), x1) in_f_2(x0, go_up(x1)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (53) TransformationProof (SOUND) By narrowing [LPAR04] the rule TOP(go_up(x)) -> TOP(reduce(x)) at position [0] we obtained the following new rules [LPAR04]: (TOP(go_up(f(x0, x1))) -> TOP(check_f(redex_f(x0, x1))),TOP(go_up(f(x0, x1))) -> TOP(check_f(redex_f(x0, x1)))) (TOP(go_up(0)) -> TOP(go_up(2)),TOP(go_up(0)) -> TOP(go_up(2))) (TOP(go_up(1)) -> TOP(go_up(2)),TOP(go_up(1)) -> TOP(go_up(2))) ---------------------------------------- (54) Obligation: Q DP problem: The TRS P consists of the following rules: TOP(go_up(f(x0, x1))) -> TOP(check_f(redex_f(x0, x1))) TOP(go_up(0)) -> TOP(go_up(2)) TOP(go_up(1)) -> TOP(go_up(2)) The TRS R consists of the following rules: reduce(f(x_1, x_2)) -> check_f(redex_f(x_1, x_2)) reduce(0) -> go_up(2) reduce(1) -> go_up(2) redex_f(x, x) -> result_f(f(0, 1)) check_f(result_f(x)) -> go_up(x) check_f(redex_f(x_1, x_2)) -> in_f_1(reduce(x_1), x_2) check_f(redex_f(x_1, x_2)) -> in_f_2(x_1, reduce(x_2)) in_f_2(x_1, go_up(x_2)) -> go_up(f(x_1, x_2)) in_f_1(go_up(x_1), x_2) -> go_up(f(x_1, x_2)) The set Q consists of the following terms: reduce(f(x0, x1)) redex_f(x0, x0) reduce(0) reduce(1) redex_f(x0, 2) redex_f(2, x0) check_f(result_f(x0)) check_f(redex_f(x0, x1)) in_f_1(go_up(x0), x1) in_f_2(x0, go_up(x1)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (55) DependencyGraphProof (EQUIVALENT) The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 1 SCC with 2 less nodes. ---------------------------------------- (56) Obligation: Q DP problem: The TRS P consists of the following rules: TOP(go_up(f(x0, x1))) -> TOP(check_f(redex_f(x0, x1))) The TRS R consists of the following rules: reduce(f(x_1, x_2)) -> check_f(redex_f(x_1, x_2)) reduce(0) -> go_up(2) reduce(1) -> go_up(2) redex_f(x, x) -> result_f(f(0, 1)) check_f(result_f(x)) -> go_up(x) check_f(redex_f(x_1, x_2)) -> in_f_1(reduce(x_1), x_2) check_f(redex_f(x_1, x_2)) -> in_f_2(x_1, reduce(x_2)) in_f_2(x_1, go_up(x_2)) -> go_up(f(x_1, x_2)) in_f_1(go_up(x_1), x_2) -> go_up(f(x_1, x_2)) The set Q consists of the following terms: reduce(f(x0, x1)) redex_f(x0, x0) reduce(0) reduce(1) redex_f(x0, 2) redex_f(2, x0) check_f(result_f(x0)) check_f(redex_f(x0, x1)) in_f_1(go_up(x0), x1) in_f_2(x0, go_up(x1)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (57) 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. ---------------------------------------- (58) Obligation: Q DP problem: The TRS P consists of the following rules: TOP(go_up(x)) -> TOP(reduce(x)) The TRS R consists of the following rules: reduce(f(x_1, x_2)) -> check_f(redex_f(x_1, x_2)) reduce(0) -> go_up(2) reduce(1) -> go_up(2) redex_f(x, x) -> result_f(f(0, 1)) check_f(result_f(x)) -> go_up(x) check_f(redex_f(x_1, x_2)) -> in_f_1(reduce(x_1), x_2) check_f(redex_f(x_1, x_2)) -> in_f_2(x_1, reduce(x_2)) in_f_2(x_1, go_up(x_2)) -> go_up(f(x_1, x_2)) in_f_1(go_up(x_1), x_2) -> go_up(f(x_1, x_2)) The set Q consists of the following terms: top(go_up(x0)) reduce(f(x0, x1)) redex_f(x0, x0) reduce(0) reduce(1) redex_f(x0, 2) redex_f(2, x0) check_f(result_f(x0)) check_f(redex_f(x0, x1)) in_f_1(go_up(x0), x1) in_f_2(x0, go_up(x1)) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (59) 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]. top(go_up(x0)) ---------------------------------------- (60) Obligation: Q DP problem: The TRS P consists of the following rules: TOP(go_up(x)) -> TOP(reduce(x)) The TRS R consists of the following rules: reduce(f(x_1, x_2)) -> check_f(redex_f(x_1, x_2)) reduce(0) -> go_up(2) reduce(1) -> go_up(2) redex_f(x, x) -> result_f(f(0, 1)) check_f(result_f(x)) -> go_up(x) check_f(redex_f(x_1, x_2)) -> in_f_1(reduce(x_1), x_2) check_f(redex_f(x_1, x_2)) -> in_f_2(x_1, reduce(x_2)) in_f_2(x_1, go_up(x_2)) -> go_up(f(x_1, x_2)) in_f_1(go_up(x_1), x_2) -> go_up(f(x_1, x_2)) The set Q consists of the following terms: reduce(f(x0, x1)) redex_f(x0, x0) reduce(0) reduce(1) redex_f(x0, 2) redex_f(2, x0) check_f(result_f(x0)) check_f(redex_f(x0, x1)) in_f_1(go_up(x0), x1) in_f_2(x0, go_up(x1)) We have to consider all minimal (P,Q,R)-chains.