YES (ignored inputs)COMMENT translated from Cops 170 *** Computating Strongly Quasi-Reducible Parts *** TRS: [ +(0,?y) -> ?y, +(s(?x),?y) -> s(+(?x,?y)), +(+(?x,?y),?z) -> +(?x,+(?y,?z)), +(?x,?y) -> +(?y,?x), s(s(?x)) -> s(?x), s(?x) -> s(s(?x)) ] Constructors: {0,s} Defined function symbols: {+} Constructor subsystem: [ s(s(?x)) -> s(?x) ] Rule part & Conj Part: [ s(s(?x)) -> s(?x), +(0,?y) -> ?y, +(s(?x),?y) -> s(+(?x,?y)) ] [ +(+(?x,?y),?z) -> +(?x,+(?y,?z)), +(?x,?y) -> +(?y,?x), s(?x) -> s(s(?x)) ] *** Ground Confluence Check by Rewriting Induction *** Sort: {Nat} Signature: [ + : Nat,Nat -> Nat, 0 : Nat, s : Nat -> Nat ] Rule Part: [ s(s(?x)) -> s(?x), +(0,?y) -> ?y, +(s(?x),?y) -> s(+(?x,?y)) ] Conjecture Part: [ +(+(?x,?y),?z) = +(?x,+(?y,?z)), +(?x,?y) = +(?y,?x), s(?x) = s(s(?x)) ] Precedence (by weight): {(+,3),(0,2),(s,0)} Rule part is confluent. R0 is ground confluent. Check conj part consists of inductive theorems of R0. Rules: [ s(s(?x)) -> s(?x), +(0,?y) -> ?y, +(s(?x),?y) -> s(+(?x,?y)) ] Conjectures: [ +(+(?x,?y),?z) = +(?x,+(?y,?z)), +(?x,?y) = +(?y,?x), s(?x) = s(s(?x)) ] STEP 0 ES: [ +(+(?x,?y),?z) = +(?x,+(?y,?z)), +(?x,?y) = +(?y,?x), s(?x) = s(s(?x)) ] HS: [ ] ES0: [ +(+(?x,?y),?z) = +(?x,+(?y,?z)), +(?x,?y) = +(?y,?x), s(?x) = s(?x) ] HS0: [ ] ES1: [ +(+(?x,?y),?z) = +(?x,+(?y,?z)), +(?x,?y) = +(?y,?x) ] HS1: [ ] Expand +(?x,?y) = +(?y,?x) [ ?y_2 = +(?y_2,0), s(+(?x_3,?y_3)) = +(?y_3,s(?x_3)) ] ES2: [ ?y_2 = +(?y_2,0), s(+(?x_3,?y_3)) = +(?y_3,s(?x_3)), +(+(?x,?y),?z) = +(?x,+(?y,?z)) ] HS2: [ +(?x,?y) -> +(?y,?x) ] STEP 1 ES: [ ?y_2 = +(?y_2,0), s(+(?x_3,?y_3)) = +(?y_3,s(?x_3)), +(+(?x,?y),?z) = +(?x,+(?y,?z)) ] HS: [ +(?x,?y) -> +(?y,?x) ] ES0: [ ?y_2 = +(?y_2,0), s(+(?x_3,?y_3)) = +(?y_3,s(?x_3)), +(+(?x,?y),?z) = +(?x,+(?y,?z)) ] HS0: [ +(?x,?y) -> +(?y,?x) ] ES1: [ ?y_2 = +(?y_2,0), s(+(?x_3,?y_3)) = +(?y_3,s(?x_3)), +(+(?x,?y),?z) = +(?x,+(?y,?z)) ] HS1: [ +(?x,?y) -> +(?y,?x) ] Expand +(?y_2,0) = ?y_2 [ 0 = 0, s(+(?x_3,0)) = s(?x_3) ] ES2: [ 0 = 0, s(+(?x_3,0)) = s(?x_3), +(+(?x,?y),?z) = +(?x,+(?y,?z)), s(+(?x_3,?y_3)) = +(?y_3,s(?x_3)) ] HS2: [ +(?y_2,0) -> ?y_2, +(?x,?y) -> +(?y,?x) ] STEP 2 ES: [ 0 = 0, s(+(?x_3,0)) = s(?x_3), +(+(?x,?y),?z) = +(?x,+(?y,?z)), s(+(?x_3,?y_3)) = +(?y_3,s(?x_3)) ] HS: [ +(?y_2,0) -> ?y_2, +(?x,?y) -> +(?y,?x) ] ES0: [ 0 = 0, s(?x_3) = s(?x_3), +(+(?x,?y),?z) = +(?x,+(?y,?z)), s(+(?x_3,?y_3)) = +(?y_3,s(?x_3)) ] HS0: [ +(?y_2,0) -> ?y_2, +(?x,?y) -> +(?y,?x) ] ES1: [ +(+(?x,?y),?z) = +(?x,+(?y,?z)), s(+(?x_3,?y_3)) = +(?y_3,s(?x_3)) ] HS1: [ +(?y_2,0) -> ?y_2, +(?x,?y) -> +(?y,?x) ] Expand +(?y_3,s(?x_3)) = s(+(?x_3,?y_3)) [ s(?x) = s(+(?x,0)), s(+(?x_3,s(?x))) = s(+(?x,s(?x_3))) ] ES2: [ s(?x) = s(+(?x,0)), s(+(?x_3,s(?x))) = s(+(?x,s(?x_3))), +(+(?x,?y),?z) = +(?x,+(?y,?z)) ] HS2: [ +(?y_3,s(?x_3)) -> s(+(?x_3,?y_3)), +(?y_2,0) -> ?y_2, +(?x,?y) -> +(?y,?x) ] STEP 3 ES: [ s(?x) = s(+(?x,0)), s(+(?x_3,s(?x))) = s(+(?x,s(?x_3))), +(+(?x,?y),?z) = +(?x,+(?y,?z)) ] HS: [ +(?y_3,s(?x_3)) -> s(+(?x_3,?y_3)), +(?y_2,0) -> ?y_2, +(?x,?y) -> +(?y,?x) ] ES0: [ s(?x) = s(?x), s(+(?x,?x_3)) = s(+(?x_3,?x)), +(+(?x,?y),?z) = +(?x,+(?y,?z)) ] HS0: [ +(?y_3,s(?x_3)) -> s(+(?x_3,?y_3)), +(?y_2,0) -> ?y_2, +(?x,?y) -> +(?y,?x) ] ES1: [ +(+(?x,?y),?z) = +(?x,+(?y,?z)) ] HS1: [ +(?y_3,s(?x_3)) -> s(+(?x_3,?y_3)), +(?y_2,0) -> ?y_2, +(?x,?y) -> +(?y,?x) ] Expand +(+(?x,?y),?z) = +(?x,+(?y,?z)) [ +(?y_2,?z) = +(0,+(?y_2,?z)), +(s(+(?x_3,?y_3)),?z) = +(s(?x_3),+(?y_3,?z)) ] ES2: [ +(?y_2,?z) = +(0,+(?y_2,?z)), s(+(+(?x_3,?y_3),?z)) = +(s(?x_3),+(?y_3,?z)) ] HS2: [ +(+(?x,?y),?z) -> +(?x,+(?y,?z)), +(?y_3,s(?x_3)) -> s(+(?x_3,?y_3)), +(?y_2,0) -> ?y_2, +(?x,?y) -> +(?y,?x) ] STEP 4 ES: [ +(?y_2,?z) = +(0,+(?y_2,?z)), s(+(+(?x_3,?y_3),?z)) = +(s(?x_3),+(?y_3,?z)) ] HS: [ +(+(?x,?y),?z) -> +(?x,+(?y,?z)), +(?y_3,s(?x_3)) -> s(+(?x_3,?y_3)), +(?y_2,0) -> ?y_2, +(?x,?y) -> +(?y,?x) ] ES0: [ +(?y_2,?z) = +(?y_2,?z), s(+(+(?x_3,?y_3),?z)) = s(+(?x_3,+(?y_3,?z))) ] HS0: [ +(+(?x,?y),?z) -> +(?x,+(?y,?z)), +(?y_3,s(?x_3)) -> s(+(?x_3,?y_3)), +(?y_2,0) -> ?y_2, +(?x,?y) -> +(?y,?x) ] ES1: [ ] HS1: [ +(+(?x,?y),?z) -> +(?x,+(?y,?z)), +(?y_3,s(?x_3)) -> s(+(?x_3,?y_3)), +(?y_2,0) -> ?y_2, +(?x,?y) -> +(?y,?x) ] Conj part consisits of inductive theorems of R0. examples/fromCops/cr/170.trs: Success(GCR) (12 msec.)