/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# AProVE Commit ID: 48fb2092695e11cc9f56e44b17a92a5f88ffb256 marcel 20180622 unpublished dirty Termination w.r.t. Q of the given QTRS could be proven: (0) QTRS (1) Overlay + Local Confluence [EQUIVALENT, 0 ms] (2) QTRS (3) DependencyPairsProof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) TransformationProof [EQUIVALENT, 0 ms] (27) QDP (28) DependencyGraphProof [EQUIVALENT, 0 ms] (29) QDP (30) UsableRulesProof [EQUIVALENT, 0 ms] (31) QDP (32) QReductionProof [EQUIVALENT, 0 ms] (33) QDP (34) TransformationProof [EQUIVALENT, 0 ms] (35) QDP (36) TransformationProof [EQUIVALENT, 0 ms] (37) QDP (38) TransformationProof [EQUIVALENT, 0 ms] (39) QDP (40) UsableRulesProof [EQUIVALENT, 0 ms] (41) QDP (42) QReductionProof [EQUIVALENT, 0 ms] (43) QDP (44) TransformationProof [EQUIVALENT, 0 ms] (45) QDP (46) UsableRulesProof [EQUIVALENT, 0 ms] (47) QDP (48) QReductionProof [EQUIVALENT, 0 ms] (49) QDP (50) TransformationProof [EQUIVALENT, 0 ms] (51) QDP (52) UsableRulesProof [EQUIVALENT, 0 ms] (53) QDP (54) QReductionProof [EQUIVALENT, 0 ms] (55) QDP (56) TransformationProof [EQUIVALENT, 0 ms] (57) QDP (58) UsableRulesProof [EQUIVALENT, 0 ms] (59) QDP (60) TransformationProof [EQUIVALENT, 0 ms] (61) QDP (62) QDPOrderProof [EQUIVALENT, 0 ms] (63) QDP (64) DependencyGraphProof [EQUIVALENT, 0 ms] (65) QDP (66) QDPOrderProof [EQUIVALENT, 14 ms] (67) QDP (68) DependencyGraphProof [EQUIVALENT, 0 ms] (69) TRUE ---------------------------------------- (0) Obligation: Q restricted rewrite system: The TRS R consists of the following rules: isEmpty(cons(x, xs)) -> false isEmpty(nil) -> true isZero(0) -> true isZero(s(x)) -> false head(cons(x, xs)) -> x tail(cons(x, xs)) -> xs tail(nil) -> nil p(s(s(x))) -> s(p(s(x))) p(s(0)) -> 0 p(0) -> 0 inc(s(x)) -> s(inc(x)) inc(0) -> s(0) sumList(xs, y) -> if(isEmpty(xs), isZero(head(xs)), y, tail(xs), cons(p(head(xs)), tail(xs)), inc(y)) if(true, b, y, xs, ys, x) -> y if(false, true, y, xs, ys, x) -> sumList(xs, y) if(false, false, y, xs, ys, x) -> sumList(ys, x) sum(xs) -> sumList(xs, 0) 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: isEmpty(cons(x, xs)) -> false isEmpty(nil) -> true isZero(0) -> true isZero(s(x)) -> false head(cons(x, xs)) -> x tail(cons(x, xs)) -> xs tail(nil) -> nil p(s(s(x))) -> s(p(s(x))) p(s(0)) -> 0 p(0) -> 0 inc(s(x)) -> s(inc(x)) inc(0) -> s(0) sumList(xs, y) -> if(isEmpty(xs), isZero(head(xs)), y, tail(xs), cons(p(head(xs)), tail(xs)), inc(y)) if(true, b, y, xs, ys, x) -> y if(false, true, y, xs, ys, x) -> sumList(xs, y) if(false, false, y, xs, ys, x) -> sumList(ys, x) sum(xs) -> sumList(xs, 0) The set Q consists of the following terms: isEmpty(cons(x0, x1)) isEmpty(nil) isZero(0) isZero(s(x0)) head(cons(x0, x1)) tail(cons(x0, x1)) tail(nil) p(s(s(x0))) p(s(0)) p(0) inc(s(x0)) inc(0) sumList(x0, x1) if(true, x0, x1, x2, x3, x4) if(false, true, x0, x1, x2, x3) if(false, false, x0, x1, x2, x3) sum(x0) ---------------------------------------- (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: P(s(s(x))) -> P(s(x)) INC(s(x)) -> INC(x) SUMLIST(xs, y) -> IF(isEmpty(xs), isZero(head(xs)), y, tail(xs), cons(p(head(xs)), tail(xs)), inc(y)) SUMLIST(xs, y) -> ISEMPTY(xs) SUMLIST(xs, y) -> ISZERO(head(xs)) SUMLIST(xs, y) -> HEAD(xs) SUMLIST(xs, y) -> TAIL(xs) SUMLIST(xs, y) -> P(head(xs)) SUMLIST(xs, y) -> INC(y) IF(false, true, y, xs, ys, x) -> SUMLIST(xs, y) IF(false, false, y, xs, ys, x) -> SUMLIST(ys, x) SUM(xs) -> SUMLIST(xs, 0) The TRS R consists of the following rules: isEmpty(cons(x, xs)) -> false isEmpty(nil) -> true isZero(0) -> true isZero(s(x)) -> false head(cons(x, xs)) -> x tail(cons(x, xs)) -> xs tail(nil) -> nil p(s(s(x))) -> s(p(s(x))) p(s(0)) -> 0 p(0) -> 0 inc(s(x)) -> s(inc(x)) inc(0) -> s(0) sumList(xs, y) -> if(isEmpty(xs), isZero(head(xs)), y, tail(xs), cons(p(head(xs)), tail(xs)), inc(y)) if(true, b, y, xs, ys, x) -> y if(false, true, y, xs, ys, x) -> sumList(xs, y) if(false, false, y, xs, ys, x) -> sumList(ys, x) sum(xs) -> sumList(xs, 0) The set Q consists of the following terms: isEmpty(cons(x0, x1)) isEmpty(nil) isZero(0) isZero(s(x0)) head(cons(x0, x1)) tail(cons(x0, x1)) tail(nil) p(s(s(x0))) p(s(0)) p(0) inc(s(x0)) inc(0) sumList(x0, x1) if(true, x0, x1, x2, x3, x4) if(false, true, x0, x1, x2, x3) if(false, false, x0, x1, x2, x3) sum(x0) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (5) DependencyGraphProof (EQUIVALENT) The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 3 SCCs with 7 less nodes. ---------------------------------------- (6) Complex Obligation (AND) ---------------------------------------- (7) Obligation: Q DP problem: The TRS P consists of the following rules: INC(s(x)) -> INC(x) The TRS R consists of the following rules: isEmpty(cons(x, xs)) -> false isEmpty(nil) -> true isZero(0) -> true isZero(s(x)) -> false head(cons(x, xs)) -> x tail(cons(x, xs)) -> xs tail(nil) -> nil p(s(s(x))) -> s(p(s(x))) p(s(0)) -> 0 p(0) -> 0 inc(s(x)) -> s(inc(x)) inc(0) -> s(0) sumList(xs, y) -> if(isEmpty(xs), isZero(head(xs)), y, tail(xs), cons(p(head(xs)), tail(xs)), inc(y)) if(true, b, y, xs, ys, x) -> y if(false, true, y, xs, ys, x) -> sumList(xs, y) if(false, false, y, xs, ys, x) -> sumList(ys, x) sum(xs) -> sumList(xs, 0) The set Q consists of the following terms: isEmpty(cons(x0, x1)) isEmpty(nil) isZero(0) isZero(s(x0)) head(cons(x0, x1)) tail(cons(x0, x1)) tail(nil) p(s(s(x0))) p(s(0)) p(0) inc(s(x0)) inc(0) sumList(x0, x1) if(true, x0, x1, x2, x3, x4) if(false, true, x0, x1, x2, x3) if(false, false, x0, x1, x2, x3) sum(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: INC(s(x)) -> INC(x) R is empty. The set Q consists of the following terms: isEmpty(cons(x0, x1)) isEmpty(nil) isZero(0) isZero(s(x0)) head(cons(x0, x1)) tail(cons(x0, x1)) tail(nil) p(s(s(x0))) p(s(0)) p(0) inc(s(x0)) inc(0) sumList(x0, x1) if(true, x0, x1, x2, x3, x4) if(false, true, x0, x1, x2, x3) if(false, false, x0, x1, x2, x3) sum(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]. isEmpty(cons(x0, x1)) isEmpty(nil) isZero(0) isZero(s(x0)) head(cons(x0, x1)) tail(cons(x0, x1)) tail(nil) p(s(s(x0))) p(s(0)) p(0) inc(s(x0)) inc(0) sumList(x0, x1) if(true, x0, x1, x2, x3, x4) if(false, true, x0, x1, x2, x3) if(false, false, x0, x1, x2, x3) sum(x0) ---------------------------------------- (11) Obligation: Q DP problem: The TRS P consists of the following rules: INC(s(x)) -> INC(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: *INC(s(x)) -> INC(x) The graph contains the following edges 1 > 1 ---------------------------------------- (13) YES ---------------------------------------- (14) Obligation: Q DP problem: The TRS P consists of the following rules: P(s(s(x))) -> P(s(x)) The TRS R consists of the following rules: isEmpty(cons(x, xs)) -> false isEmpty(nil) -> true isZero(0) -> true isZero(s(x)) -> false head(cons(x, xs)) -> x tail(cons(x, xs)) -> xs tail(nil) -> nil p(s(s(x))) -> s(p(s(x))) p(s(0)) -> 0 p(0) -> 0 inc(s(x)) -> s(inc(x)) inc(0) -> s(0) sumList(xs, y) -> if(isEmpty(xs), isZero(head(xs)), y, tail(xs), cons(p(head(xs)), tail(xs)), inc(y)) if(true, b, y, xs, ys, x) -> y if(false, true, y, xs, ys, x) -> sumList(xs, y) if(false, false, y, xs, ys, x) -> sumList(ys, x) sum(xs) -> sumList(xs, 0) The set Q consists of the following terms: isEmpty(cons(x0, x1)) isEmpty(nil) isZero(0) isZero(s(x0)) head(cons(x0, x1)) tail(cons(x0, x1)) tail(nil) p(s(s(x0))) p(s(0)) p(0) inc(s(x0)) inc(0) sumList(x0, x1) if(true, x0, x1, x2, x3, x4) if(false, true, x0, x1, x2, x3) if(false, false, x0, x1, x2, x3) sum(x0) 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: P(s(s(x))) -> P(s(x)) R is empty. The set Q consists of the following terms: isEmpty(cons(x0, x1)) isEmpty(nil) isZero(0) isZero(s(x0)) head(cons(x0, x1)) tail(cons(x0, x1)) tail(nil) p(s(s(x0))) p(s(0)) p(0) inc(s(x0)) inc(0) sumList(x0, x1) if(true, x0, x1, x2, x3, x4) if(false, true, x0, x1, x2, x3) if(false, false, x0, x1, x2, x3) sum(x0) 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]. isEmpty(cons(x0, x1)) isEmpty(nil) isZero(0) isZero(s(x0)) head(cons(x0, x1)) tail(cons(x0, x1)) tail(nil) p(s(s(x0))) p(s(0)) p(0) inc(s(x0)) inc(0) sumList(x0, x1) if(true, x0, x1, x2, x3, x4) if(false, true, x0, x1, x2, x3) if(false, false, x0, x1, x2, x3) sum(x0) ---------------------------------------- (18) Obligation: Q DP problem: The TRS P consists of the following rules: P(s(s(x))) -> P(s(x)) 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: *P(s(s(x))) -> P(s(x)) The graph contains the following edges 1 > 1 ---------------------------------------- (20) YES ---------------------------------------- (21) Obligation: Q DP problem: The TRS P consists of the following rules: SUMLIST(xs, y) -> IF(isEmpty(xs), isZero(head(xs)), y, tail(xs), cons(p(head(xs)), tail(xs)), inc(y)) IF(false, true, y, xs, ys, x) -> SUMLIST(xs, y) IF(false, false, y, xs, ys, x) -> SUMLIST(ys, x) The TRS R consists of the following rules: isEmpty(cons(x, xs)) -> false isEmpty(nil) -> true isZero(0) -> true isZero(s(x)) -> false head(cons(x, xs)) -> x tail(cons(x, xs)) -> xs tail(nil) -> nil p(s(s(x))) -> s(p(s(x))) p(s(0)) -> 0 p(0) -> 0 inc(s(x)) -> s(inc(x)) inc(0) -> s(0) sumList(xs, y) -> if(isEmpty(xs), isZero(head(xs)), y, tail(xs), cons(p(head(xs)), tail(xs)), inc(y)) if(true, b, y, xs, ys, x) -> y if(false, true, y, xs, ys, x) -> sumList(xs, y) if(false, false, y, xs, ys, x) -> sumList(ys, x) sum(xs) -> sumList(xs, 0) The set Q consists of the following terms: isEmpty(cons(x0, x1)) isEmpty(nil) isZero(0) isZero(s(x0)) head(cons(x0, x1)) tail(cons(x0, x1)) tail(nil) p(s(s(x0))) p(s(0)) p(0) inc(s(x0)) inc(0) sumList(x0, x1) if(true, x0, x1, x2, x3, x4) if(false, true, x0, x1, x2, x3) if(false, false, x0, x1, x2, x3) sum(x0) 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: SUMLIST(xs, y) -> IF(isEmpty(xs), isZero(head(xs)), y, tail(xs), cons(p(head(xs)), tail(xs)), inc(y)) IF(false, true, y, xs, ys, x) -> SUMLIST(xs, y) IF(false, false, y, xs, ys, x) -> SUMLIST(ys, x) The TRS R consists of the following rules: isEmpty(cons(x, xs)) -> false isEmpty(nil) -> true head(cons(x, xs)) -> x isZero(0) -> true isZero(s(x)) -> false tail(cons(x, xs)) -> xs tail(nil) -> nil p(s(s(x))) -> s(p(s(x))) p(s(0)) -> 0 p(0) -> 0 inc(s(x)) -> s(inc(x)) inc(0) -> s(0) The set Q consists of the following terms: isEmpty(cons(x0, x1)) isEmpty(nil) isZero(0) isZero(s(x0)) head(cons(x0, x1)) tail(cons(x0, x1)) tail(nil) p(s(s(x0))) p(s(0)) p(0) inc(s(x0)) inc(0) sumList(x0, x1) if(true, x0, x1, x2, x3, x4) if(false, true, x0, x1, x2, x3) if(false, false, x0, x1, x2, x3) sum(x0) 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]. sumList(x0, x1) if(true, x0, x1, x2, x3, x4) if(false, true, x0, x1, x2, x3) if(false, false, x0, x1, x2, x3) sum(x0) ---------------------------------------- (25) Obligation: Q DP problem: The TRS P consists of the following rules: SUMLIST(xs, y) -> IF(isEmpty(xs), isZero(head(xs)), y, tail(xs), cons(p(head(xs)), tail(xs)), inc(y)) IF(false, true, y, xs, ys, x) -> SUMLIST(xs, y) IF(false, false, y, xs, ys, x) -> SUMLIST(ys, x) The TRS R consists of the following rules: isEmpty(cons(x, xs)) -> false isEmpty(nil) -> true head(cons(x, xs)) -> x isZero(0) -> true isZero(s(x)) -> false tail(cons(x, xs)) -> xs tail(nil) -> nil p(s(s(x))) -> s(p(s(x))) p(s(0)) -> 0 p(0) -> 0 inc(s(x)) -> s(inc(x)) inc(0) -> s(0) The set Q consists of the following terms: isEmpty(cons(x0, x1)) isEmpty(nil) isZero(0) isZero(s(x0)) head(cons(x0, x1)) tail(cons(x0, x1)) tail(nil) p(s(s(x0))) p(s(0)) p(0) inc(s(x0)) inc(0) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (26) TransformationProof (EQUIVALENT) By narrowing [LPAR04] the rule SUMLIST(xs, y) -> IF(isEmpty(xs), isZero(head(xs)), y, tail(xs), cons(p(head(xs)), tail(xs)), inc(y)) at position [0] we obtained the following new rules [LPAR04]: (SUMLIST(cons(x0, x1), y1) -> IF(false, isZero(head(cons(x0, x1))), y1, tail(cons(x0, x1)), cons(p(head(cons(x0, x1))), tail(cons(x0, x1))), inc(y1)),SUMLIST(cons(x0, x1), y1) -> IF(false, isZero(head(cons(x0, x1))), y1, tail(cons(x0, x1)), cons(p(head(cons(x0, x1))), tail(cons(x0, x1))), inc(y1))) (SUMLIST(nil, y1) -> IF(true, isZero(head(nil)), y1, tail(nil), cons(p(head(nil)), tail(nil)), inc(y1)),SUMLIST(nil, y1) -> IF(true, isZero(head(nil)), y1, tail(nil), cons(p(head(nil)), tail(nil)), inc(y1))) ---------------------------------------- (27) Obligation: Q DP problem: The TRS P consists of the following rules: IF(false, true, y, xs, ys, x) -> SUMLIST(xs, y) IF(false, false, y, xs, ys, x) -> SUMLIST(ys, x) SUMLIST(cons(x0, x1), y1) -> IF(false, isZero(head(cons(x0, x1))), y1, tail(cons(x0, x1)), cons(p(head(cons(x0, x1))), tail(cons(x0, x1))), inc(y1)) SUMLIST(nil, y1) -> IF(true, isZero(head(nil)), y1, tail(nil), cons(p(head(nil)), tail(nil)), inc(y1)) The TRS R consists of the following rules: isEmpty(cons(x, xs)) -> false isEmpty(nil) -> true head(cons(x, xs)) -> x isZero(0) -> true isZero(s(x)) -> false tail(cons(x, xs)) -> xs tail(nil) -> nil p(s(s(x))) -> s(p(s(x))) p(s(0)) -> 0 p(0) -> 0 inc(s(x)) -> s(inc(x)) inc(0) -> s(0) The set Q consists of the following terms: isEmpty(cons(x0, x1)) isEmpty(nil) isZero(0) isZero(s(x0)) head(cons(x0, x1)) tail(cons(x0, x1)) tail(nil) p(s(s(x0))) p(s(0)) p(0) inc(s(x0)) inc(0) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (28) DependencyGraphProof (EQUIVALENT) The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 1 SCC with 1 less node. ---------------------------------------- (29) Obligation: Q DP problem: The TRS P consists of the following rules: SUMLIST(cons(x0, x1), y1) -> IF(false, isZero(head(cons(x0, x1))), y1, tail(cons(x0, x1)), cons(p(head(cons(x0, x1))), tail(cons(x0, x1))), inc(y1)) IF(false, true, y, xs, ys, x) -> SUMLIST(xs, y) IF(false, false, y, xs, ys, x) -> SUMLIST(ys, x) The TRS R consists of the following rules: isEmpty(cons(x, xs)) -> false isEmpty(nil) -> true head(cons(x, xs)) -> x isZero(0) -> true isZero(s(x)) -> false tail(cons(x, xs)) -> xs tail(nil) -> nil p(s(s(x))) -> s(p(s(x))) p(s(0)) -> 0 p(0) -> 0 inc(s(x)) -> s(inc(x)) inc(0) -> s(0) The set Q consists of the following terms: isEmpty(cons(x0, x1)) isEmpty(nil) isZero(0) isZero(s(x0)) head(cons(x0, x1)) tail(cons(x0, x1)) tail(nil) p(s(s(x0))) p(s(0)) p(0) inc(s(x0)) inc(0) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (30) 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. ---------------------------------------- (31) Obligation: Q DP problem: The TRS P consists of the following rules: SUMLIST(cons(x0, x1), y1) -> IF(false, isZero(head(cons(x0, x1))), y1, tail(cons(x0, x1)), cons(p(head(cons(x0, x1))), tail(cons(x0, x1))), inc(y1)) IF(false, true, y, xs, ys, x) -> SUMLIST(xs, y) IF(false, false, y, xs, ys, x) -> SUMLIST(ys, x) The TRS R consists of the following rules: head(cons(x, xs)) -> x isZero(0) -> true isZero(s(x)) -> false tail(cons(x, xs)) -> xs p(s(s(x))) -> s(p(s(x))) p(s(0)) -> 0 p(0) -> 0 inc(s(x)) -> s(inc(x)) inc(0) -> s(0) The set Q consists of the following terms: isEmpty(cons(x0, x1)) isEmpty(nil) isZero(0) isZero(s(x0)) head(cons(x0, x1)) tail(cons(x0, x1)) tail(nil) p(s(s(x0))) p(s(0)) p(0) inc(s(x0)) inc(0) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (32) 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]. isEmpty(cons(x0, x1)) isEmpty(nil) ---------------------------------------- (33) Obligation: Q DP problem: The TRS P consists of the following rules: SUMLIST(cons(x0, x1), y1) -> IF(false, isZero(head(cons(x0, x1))), y1, tail(cons(x0, x1)), cons(p(head(cons(x0, x1))), tail(cons(x0, x1))), inc(y1)) IF(false, true, y, xs, ys, x) -> SUMLIST(xs, y) IF(false, false, y, xs, ys, x) -> SUMLIST(ys, x) The TRS R consists of the following rules: head(cons(x, xs)) -> x isZero(0) -> true isZero(s(x)) -> false tail(cons(x, xs)) -> xs p(s(s(x))) -> s(p(s(x))) p(s(0)) -> 0 p(0) -> 0 inc(s(x)) -> s(inc(x)) inc(0) -> s(0) The set Q consists of the following terms: isZero(0) isZero(s(x0)) head(cons(x0, x1)) tail(cons(x0, x1)) tail(nil) p(s(s(x0))) p(s(0)) p(0) inc(s(x0)) inc(0) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (34) TransformationProof (EQUIVALENT) By rewriting [LPAR04] the rule SUMLIST(cons(x0, x1), y1) -> IF(false, isZero(head(cons(x0, x1))), y1, tail(cons(x0, x1)), cons(p(head(cons(x0, x1))), tail(cons(x0, x1))), inc(y1)) at position [1,0] we obtained the following new rules [LPAR04]: (SUMLIST(cons(x0, x1), y1) -> IF(false, isZero(x0), y1, tail(cons(x0, x1)), cons(p(head(cons(x0, x1))), tail(cons(x0, x1))), inc(y1)),SUMLIST(cons(x0, x1), y1) -> IF(false, isZero(x0), y1, tail(cons(x0, x1)), cons(p(head(cons(x0, x1))), tail(cons(x0, x1))), inc(y1))) ---------------------------------------- (35) Obligation: Q DP problem: The TRS P consists of the following rules: IF(false, true, y, xs, ys, x) -> SUMLIST(xs, y) IF(false, false, y, xs, ys, x) -> SUMLIST(ys, x) SUMLIST(cons(x0, x1), y1) -> IF(false, isZero(x0), y1, tail(cons(x0, x1)), cons(p(head(cons(x0, x1))), tail(cons(x0, x1))), inc(y1)) The TRS R consists of the following rules: head(cons(x, xs)) -> x isZero(0) -> true isZero(s(x)) -> false tail(cons(x, xs)) -> xs p(s(s(x))) -> s(p(s(x))) p(s(0)) -> 0 p(0) -> 0 inc(s(x)) -> s(inc(x)) inc(0) -> s(0) The set Q consists of the following terms: isZero(0) isZero(s(x0)) head(cons(x0, x1)) tail(cons(x0, x1)) tail(nil) p(s(s(x0))) p(s(0)) p(0) inc(s(x0)) inc(0) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (36) TransformationProof (EQUIVALENT) By rewriting [LPAR04] the rule SUMLIST(cons(x0, x1), y1) -> IF(false, isZero(x0), y1, tail(cons(x0, x1)), cons(p(head(cons(x0, x1))), tail(cons(x0, x1))), inc(y1)) at position [3] we obtained the following new rules [LPAR04]: (SUMLIST(cons(x0, x1), y1) -> IF(false, isZero(x0), y1, x1, cons(p(head(cons(x0, x1))), tail(cons(x0, x1))), inc(y1)),SUMLIST(cons(x0, x1), y1) -> IF(false, isZero(x0), y1, x1, cons(p(head(cons(x0, x1))), tail(cons(x0, x1))), inc(y1))) ---------------------------------------- (37) Obligation: Q DP problem: The TRS P consists of the following rules: IF(false, true, y, xs, ys, x) -> SUMLIST(xs, y) IF(false, false, y, xs, ys, x) -> SUMLIST(ys, x) SUMLIST(cons(x0, x1), y1) -> IF(false, isZero(x0), y1, x1, cons(p(head(cons(x0, x1))), tail(cons(x0, x1))), inc(y1)) The TRS R consists of the following rules: head(cons(x, xs)) -> x isZero(0) -> true isZero(s(x)) -> false tail(cons(x, xs)) -> xs p(s(s(x))) -> s(p(s(x))) p(s(0)) -> 0 p(0) -> 0 inc(s(x)) -> s(inc(x)) inc(0) -> s(0) The set Q consists of the following terms: isZero(0) isZero(s(x0)) head(cons(x0, x1)) tail(cons(x0, x1)) tail(nil) p(s(s(x0))) p(s(0)) p(0) inc(s(x0)) inc(0) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (38) TransformationProof (EQUIVALENT) By rewriting [LPAR04] the rule SUMLIST(cons(x0, x1), y1) -> IF(false, isZero(x0), y1, x1, cons(p(head(cons(x0, x1))), tail(cons(x0, x1))), inc(y1)) at position [4,0,0] we obtained the following new rules [LPAR04]: (SUMLIST(cons(x0, x1), y1) -> IF(false, isZero(x0), y1, x1, cons(p(x0), tail(cons(x0, x1))), inc(y1)),SUMLIST(cons(x0, x1), y1) -> IF(false, isZero(x0), y1, x1, cons(p(x0), tail(cons(x0, x1))), inc(y1))) ---------------------------------------- (39) Obligation: Q DP problem: The TRS P consists of the following rules: IF(false, true, y, xs, ys, x) -> SUMLIST(xs, y) IF(false, false, y, xs, ys, x) -> SUMLIST(ys, x) SUMLIST(cons(x0, x1), y1) -> IF(false, isZero(x0), y1, x1, cons(p(x0), tail(cons(x0, x1))), inc(y1)) The TRS R consists of the following rules: head(cons(x, xs)) -> x isZero(0) -> true isZero(s(x)) -> false tail(cons(x, xs)) -> xs p(s(s(x))) -> s(p(s(x))) p(s(0)) -> 0 p(0) -> 0 inc(s(x)) -> s(inc(x)) inc(0) -> s(0) The set Q consists of the following terms: isZero(0) isZero(s(x0)) head(cons(x0, x1)) tail(cons(x0, x1)) tail(nil) p(s(s(x0))) p(s(0)) p(0) inc(s(x0)) inc(0) 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: IF(false, true, y, xs, ys, x) -> SUMLIST(xs, y) IF(false, false, y, xs, ys, x) -> SUMLIST(ys, x) SUMLIST(cons(x0, x1), y1) -> IF(false, isZero(x0), y1, x1, cons(p(x0), tail(cons(x0, x1))), inc(y1)) The TRS R consists of the following rules: isZero(0) -> true isZero(s(x)) -> false p(s(s(x))) -> s(p(s(x))) p(s(0)) -> 0 p(0) -> 0 tail(cons(x, xs)) -> xs inc(s(x)) -> s(inc(x)) inc(0) -> s(0) The set Q consists of the following terms: isZero(0) isZero(s(x0)) head(cons(x0, x1)) tail(cons(x0, x1)) tail(nil) p(s(s(x0))) p(s(0)) p(0) inc(s(x0)) inc(0) 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]. head(cons(x0, x1)) ---------------------------------------- (43) Obligation: Q DP problem: The TRS P consists of the following rules: IF(false, true, y, xs, ys, x) -> SUMLIST(xs, y) IF(false, false, y, xs, ys, x) -> SUMLIST(ys, x) SUMLIST(cons(x0, x1), y1) -> IF(false, isZero(x0), y1, x1, cons(p(x0), tail(cons(x0, x1))), inc(y1)) The TRS R consists of the following rules: isZero(0) -> true isZero(s(x)) -> false p(s(s(x))) -> s(p(s(x))) p(s(0)) -> 0 p(0) -> 0 tail(cons(x, xs)) -> xs inc(s(x)) -> s(inc(x)) inc(0) -> s(0) The set Q consists of the following terms: isZero(0) isZero(s(x0)) tail(cons(x0, x1)) tail(nil) p(s(s(x0))) p(s(0)) p(0) inc(s(x0)) inc(0) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (44) TransformationProof (EQUIVALENT) By rewriting [LPAR04] the rule SUMLIST(cons(x0, x1), y1) -> IF(false, isZero(x0), y1, x1, cons(p(x0), tail(cons(x0, x1))), inc(y1)) at position [4,1] we obtained the following new rules [LPAR04]: (SUMLIST(cons(x0, x1), y1) -> IF(false, isZero(x0), y1, x1, cons(p(x0), x1), inc(y1)),SUMLIST(cons(x0, x1), y1) -> IF(false, isZero(x0), y1, x1, cons(p(x0), x1), inc(y1))) ---------------------------------------- (45) Obligation: Q DP problem: The TRS P consists of the following rules: IF(false, true, y, xs, ys, x) -> SUMLIST(xs, y) IF(false, false, y, xs, ys, x) -> SUMLIST(ys, x) SUMLIST(cons(x0, x1), y1) -> IF(false, isZero(x0), y1, x1, cons(p(x0), x1), inc(y1)) The TRS R consists of the following rules: isZero(0) -> true isZero(s(x)) -> false p(s(s(x))) -> s(p(s(x))) p(s(0)) -> 0 p(0) -> 0 tail(cons(x, xs)) -> xs inc(s(x)) -> s(inc(x)) inc(0) -> s(0) The set Q consists of the following terms: isZero(0) isZero(s(x0)) tail(cons(x0, x1)) tail(nil) p(s(s(x0))) p(s(0)) p(0) inc(s(x0)) inc(0) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (46) 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. ---------------------------------------- (47) Obligation: Q DP problem: The TRS P consists of the following rules: IF(false, true, y, xs, ys, x) -> SUMLIST(xs, y) IF(false, false, y, xs, ys, x) -> SUMLIST(ys, x) SUMLIST(cons(x0, x1), y1) -> IF(false, isZero(x0), y1, x1, cons(p(x0), x1), inc(y1)) The TRS R consists of the following rules: isZero(0) -> true isZero(s(x)) -> false p(s(s(x))) -> s(p(s(x))) p(s(0)) -> 0 p(0) -> 0 inc(s(x)) -> s(inc(x)) inc(0) -> s(0) The set Q consists of the following terms: isZero(0) isZero(s(x0)) tail(cons(x0, x1)) tail(nil) p(s(s(x0))) p(s(0)) p(0) inc(s(x0)) inc(0) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (48) 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]. tail(cons(x0, x1)) tail(nil) ---------------------------------------- (49) Obligation: Q DP problem: The TRS P consists of the following rules: IF(false, true, y, xs, ys, x) -> SUMLIST(xs, y) IF(false, false, y, xs, ys, x) -> SUMLIST(ys, x) SUMLIST(cons(x0, x1), y1) -> IF(false, isZero(x0), y1, x1, cons(p(x0), x1), inc(y1)) The TRS R consists of the following rules: isZero(0) -> true isZero(s(x)) -> false p(s(s(x))) -> s(p(s(x))) p(s(0)) -> 0 p(0) -> 0 inc(s(x)) -> s(inc(x)) inc(0) -> s(0) The set Q consists of the following terms: isZero(0) isZero(s(x0)) p(s(s(x0))) p(s(0)) p(0) inc(s(x0)) inc(0) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (50) TransformationProof (EQUIVALENT) By narrowing [LPAR04] the rule SUMLIST(cons(x0, x1), y1) -> IF(false, isZero(x0), y1, x1, cons(p(x0), x1), inc(y1)) at position [1] we obtained the following new rules [LPAR04]: (SUMLIST(cons(0, y1), y2) -> IF(false, true, y2, y1, cons(p(0), y1), inc(y2)),SUMLIST(cons(0, y1), y2) -> IF(false, true, y2, y1, cons(p(0), y1), inc(y2))) (SUMLIST(cons(s(x0), y1), y2) -> IF(false, false, y2, y1, cons(p(s(x0)), y1), inc(y2)),SUMLIST(cons(s(x0), y1), y2) -> IF(false, false, y2, y1, cons(p(s(x0)), y1), inc(y2))) ---------------------------------------- (51) Obligation: Q DP problem: The TRS P consists of the following rules: IF(false, true, y, xs, ys, x) -> SUMLIST(xs, y) IF(false, false, y, xs, ys, x) -> SUMLIST(ys, x) SUMLIST(cons(0, y1), y2) -> IF(false, true, y2, y1, cons(p(0), y1), inc(y2)) SUMLIST(cons(s(x0), y1), y2) -> IF(false, false, y2, y1, cons(p(s(x0)), y1), inc(y2)) The TRS R consists of the following rules: isZero(0) -> true isZero(s(x)) -> false p(s(s(x))) -> s(p(s(x))) p(s(0)) -> 0 p(0) -> 0 inc(s(x)) -> s(inc(x)) inc(0) -> s(0) The set Q consists of the following terms: isZero(0) isZero(s(x0)) p(s(s(x0))) p(s(0)) p(0) inc(s(x0)) inc(0) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (52) 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. ---------------------------------------- (53) Obligation: Q DP problem: The TRS P consists of the following rules: IF(false, true, y, xs, ys, x) -> SUMLIST(xs, y) IF(false, false, y, xs, ys, x) -> SUMLIST(ys, x) SUMLIST(cons(0, y1), y2) -> IF(false, true, y2, y1, cons(p(0), y1), inc(y2)) SUMLIST(cons(s(x0), y1), y2) -> IF(false, false, y2, y1, cons(p(s(x0)), y1), inc(y2)) The TRS R consists of the following rules: p(s(s(x))) -> s(p(s(x))) p(s(0)) -> 0 inc(s(x)) -> s(inc(x)) inc(0) -> s(0) p(0) -> 0 The set Q consists of the following terms: isZero(0) isZero(s(x0)) p(s(s(x0))) p(s(0)) p(0) inc(s(x0)) inc(0) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (54) 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]. isZero(0) isZero(s(x0)) ---------------------------------------- (55) Obligation: Q DP problem: The TRS P consists of the following rules: IF(false, true, y, xs, ys, x) -> SUMLIST(xs, y) IF(false, false, y, xs, ys, x) -> SUMLIST(ys, x) SUMLIST(cons(0, y1), y2) -> IF(false, true, y2, y1, cons(p(0), y1), inc(y2)) SUMLIST(cons(s(x0), y1), y2) -> IF(false, false, y2, y1, cons(p(s(x0)), y1), inc(y2)) The TRS R consists of the following rules: p(s(s(x))) -> s(p(s(x))) p(s(0)) -> 0 inc(s(x)) -> s(inc(x)) inc(0) -> s(0) p(0) -> 0 The set Q consists of the following terms: p(s(s(x0))) p(s(0)) p(0) inc(s(x0)) inc(0) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (56) TransformationProof (EQUIVALENT) By rewriting [LPAR04] the rule SUMLIST(cons(0, y1), y2) -> IF(false, true, y2, y1, cons(p(0), y1), inc(y2)) at position [4,0] we obtained the following new rules [LPAR04]: (SUMLIST(cons(0, y1), y2) -> IF(false, true, y2, y1, cons(0, y1), inc(y2)),SUMLIST(cons(0, y1), y2) -> IF(false, true, y2, y1, cons(0, y1), inc(y2))) ---------------------------------------- (57) Obligation: Q DP problem: The TRS P consists of the following rules: IF(false, true, y, xs, ys, x) -> SUMLIST(xs, y) IF(false, false, y, xs, ys, x) -> SUMLIST(ys, x) SUMLIST(cons(s(x0), y1), y2) -> IF(false, false, y2, y1, cons(p(s(x0)), y1), inc(y2)) SUMLIST(cons(0, y1), y2) -> IF(false, true, y2, y1, cons(0, y1), inc(y2)) The TRS R consists of the following rules: p(s(s(x))) -> s(p(s(x))) p(s(0)) -> 0 inc(s(x)) -> s(inc(x)) inc(0) -> s(0) p(0) -> 0 The set Q consists of the following terms: p(s(s(x0))) p(s(0)) p(0) inc(s(x0)) inc(0) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (58) 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. ---------------------------------------- (59) Obligation: Q DP problem: The TRS P consists of the following rules: IF(false, true, y, xs, ys, x) -> SUMLIST(xs, y) IF(false, false, y, xs, ys, x) -> SUMLIST(ys, x) SUMLIST(cons(s(x0), y1), y2) -> IF(false, false, y2, y1, cons(p(s(x0)), y1), inc(y2)) SUMLIST(cons(0, y1), y2) -> IF(false, true, y2, y1, cons(0, y1), inc(y2)) The TRS R consists of the following rules: inc(s(x)) -> s(inc(x)) inc(0) -> s(0) p(s(s(x))) -> s(p(s(x))) p(s(0)) -> 0 The set Q consists of the following terms: p(s(s(x0))) p(s(0)) p(0) inc(s(x0)) inc(0) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (60) TransformationProof (EQUIVALENT) By instantiating [LPAR04] the rule IF(false, true, y, xs, ys, x) -> SUMLIST(xs, y) we obtained the following new rules [LPAR04]: (IF(false, true, z1, z0, cons(0, z0), y_0) -> SUMLIST(z0, z1),IF(false, true, z1, z0, cons(0, z0), y_0) -> SUMLIST(z0, z1)) ---------------------------------------- (61) Obligation: Q DP problem: The TRS P consists of the following rules: IF(false, false, y, xs, ys, x) -> SUMLIST(ys, x) SUMLIST(cons(s(x0), y1), y2) -> IF(false, false, y2, y1, cons(p(s(x0)), y1), inc(y2)) SUMLIST(cons(0, y1), y2) -> IF(false, true, y2, y1, cons(0, y1), inc(y2)) IF(false, true, z1, z0, cons(0, z0), y_0) -> SUMLIST(z0, z1) The TRS R consists of the following rules: inc(s(x)) -> s(inc(x)) inc(0) -> s(0) p(s(s(x))) -> s(p(s(x))) p(s(0)) -> 0 The set Q consists of the following terms: p(s(s(x0))) p(s(0)) p(0) inc(s(x0)) inc(0) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (62) QDPOrderProof (EQUIVALENT) We use the reduction pair processor [LPAR04,JAR06]. The following pairs can be oriented strictly and are deleted. IF(false, true, z1, z0, cons(0, z0), y_0) -> SUMLIST(z0, z1) The remaining pairs can at least be oriented weakly. Used ordering: Combined order from the following AFS and order. IF(x1, x2, x3, x4, x5, x6) = x5 SUMLIST(x1, x2) = x1 cons(x1, x2) = cons(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 ---------------------------------------- (63) Obligation: Q DP problem: The TRS P consists of the following rules: IF(false, false, y, xs, ys, x) -> SUMLIST(ys, x) SUMLIST(cons(s(x0), y1), y2) -> IF(false, false, y2, y1, cons(p(s(x0)), y1), inc(y2)) SUMLIST(cons(0, y1), y2) -> IF(false, true, y2, y1, cons(0, y1), inc(y2)) The TRS R consists of the following rules: inc(s(x)) -> s(inc(x)) inc(0) -> s(0) p(s(s(x))) -> s(p(s(x))) p(s(0)) -> 0 The set Q consists of the following terms: p(s(s(x0))) p(s(0)) p(0) inc(s(x0)) inc(0) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (64) DependencyGraphProof (EQUIVALENT) The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 1 SCC with 1 less node. ---------------------------------------- (65) Obligation: Q DP problem: The TRS P consists of the following rules: SUMLIST(cons(s(x0), y1), y2) -> IF(false, false, y2, y1, cons(p(s(x0)), y1), inc(y2)) IF(false, false, y, xs, ys, x) -> SUMLIST(ys, x) The TRS R consists of the following rules: inc(s(x)) -> s(inc(x)) inc(0) -> s(0) p(s(s(x))) -> s(p(s(x))) p(s(0)) -> 0 The set Q consists of the following terms: p(s(s(x0))) p(s(0)) p(0) inc(s(x0)) inc(0) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (66) QDPOrderProof (EQUIVALENT) We use the reduction pair processor [LPAR04,JAR06]. The following pairs can be oriented strictly and are deleted. IF(false, false, y, xs, ys, x) -> SUMLIST(ys, x) The remaining pairs can at least be oriented weakly. Used ordering: Polynomial Order [NEGPOLO,POLO] with Interpretation: POL( IF_6(x_1, ..., x_6) ) = 2x_1 + x_2 + 2x_5 + 1 POL( cons_2(x_1, x_2) ) = max{0, 2x_1 - 2} POL( p_1(x_1) ) = max{0, x_1 - 2} POL( s_1(x_1) ) = x_1 + 2 POL( 0 ) = 0 POL( inc_1(x_1) ) = 2 POL( SUMLIST_2(x_1, x_2) ) = 2x_1 POL( false ) = 1 The following usable rules [FROCOS05] with respect to the argument filtering of the ordering [JAR06] were oriented: p(s(s(x))) -> s(p(s(x))) p(s(0)) -> 0 ---------------------------------------- (67) Obligation: Q DP problem: The TRS P consists of the following rules: SUMLIST(cons(s(x0), y1), y2) -> IF(false, false, y2, y1, cons(p(s(x0)), y1), inc(y2)) The TRS R consists of the following rules: inc(s(x)) -> s(inc(x)) inc(0) -> s(0) p(s(s(x))) -> s(p(s(x))) p(s(0)) -> 0 The set Q consists of the following terms: p(s(s(x0))) p(s(0)) p(0) inc(s(x0)) inc(0) We have to consider all minimal (P,Q,R)-chains. ---------------------------------------- (68) DependencyGraphProof (EQUIVALENT) The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 0 SCCs with 1 less node. ---------------------------------------- (69) TRUE