YES (ignored inputs)COMMENT from the collection of \cite{AT2012} Rewrite Rules: [ +(?x,0) -> ?x, +(?x,s(?y)) -> s(+(?x,?y)), +(0,?y) -> ?y, +(s(?x),?y) -> s(+(?x,?y)), *(k,0) -> 0, *(k,s(?y)) -> +(k,*(k,?y)), +(?x,?y) -> +(?y,?x), +(+(?x,?y),?z) -> +(?x,+(?y,?z)) ] Apply Direct Methods... Inner CPs: [ +(?x,?z_6) = +(?x,+(0,?z_6)), +(s(+(?x_1,?y_1)),?z_6) = +(?x_1,+(s(?y_1),?z_6)), +(?y_2,?z_6) = +(0,+(?y_2,?z_6)), +(s(+(?x_3,?y_3)),?z_6) = +(s(?x_3),+(?y_3,?z_6)), +(+(?y_5,?x_5),?z_6) = +(?x_5,+(?y_5,?z_6)), +(+(?x,+(?y,?z)),?z_1) = +(+(?x,?y),+(?z,?z_1)) ] Outer CPs: [ 0 = 0, s(?x_3) = s(+(?x_3,0)), ?x = +(0,?x), +(?x_6,?y_6) = +(?x_6,+(?y_6,0)), s(+(0,?y_1)) = s(?y_1), s(+(s(?x_3),?y_1)) = s(+(?x_3,s(?y_1))), s(+(?x_1,?y_1)) = +(s(?y_1),?x_1), s(+(+(?x_6,?y_6),?y_1)) = +(?x_6,+(?y_6,s(?y_1))), ?y_2 = +(?y_2,0), s(+(?x_3,?y_3)) = +(?y_3,s(?x_3)), +(?y_5,+(?x_6,?y_6)) = +(?x_6,+(?y_6,?y_5)) ] not Overlay, check Termination... unknown/not Terminating unknown Knuth & Bendix Linear unknown Development Closed unknown Strongly Closed unknown Weakly-Non-Overlapping & Non-Collapsing & Shallow unknown Upside-Parallel-Closed/Outside-Closed (inner) Parallel CPs: (not computed) unknown Toyama (Parallel CPs) Simultaneous CPs: [ 0 = 0, s(+(?x_3,0)) = s(?x_3), +(0,?x) = ?x, +(?x_6,+(?y_6,0)) = +(?x_6,?y_6), +(?x,+(0,?z_7)) = +(?x,?z_7), s(?y) = s(+(0,?y)), s(+(?x_3,s(?y))) = s(+(s(?x_3),?y)), +(s(?y),?x) = s(+(?x,?y)), +(?x_6,+(?y_6,s(?y))) = s(+(+(?x_6,?y_6),?y)), +(?x,+(s(?y),?z_7)) = +(s(+(?x,?y)),?z_7), s(+(0,?y_2)) = s(?y_2), +(?y,0) = ?y, +(0,+(?y,?z_7)) = +(?y,?z_7), s(?x) = s(+(?x,0)), s(+(s(?x),?y_2)) = s(+(?x,s(?y_2))), +(?y,s(?x)) = s(+(?x,?y)), +(s(?x),+(?y,?z_7)) = +(s(+(?x,?y)),?z_7), ?x = +(0,?x), s(+(?x,?y_2)) = +(s(?y_2),?x), ?y = +(?y,0), s(+(?x_4,?y)) = +(?y,s(?x_4)), +(?x_6,+(?y_6,?y)) = +(?y,+(?x_6,?y_6)), +(?x,+(?y,?z_7)) = +(+(?y,?x),?z_7), +(?x_1,+(?y_1,?y)) = +(+(?x_1,?y_1),+(?y,0)), ?x = +(?x,+(0,0)), s(+(?x,?y_3)) = +(?x,+(s(?y_3),0)), ?y = +(0,+(?y,0)), s(+(?x_5,?y)) = +(s(?x_5),+(?y,0)), +(?y,?x) = +(?x,+(?y,0)), s(+(+(?x_3,+(?y_3,?y)),?y_2)) = +(+(?x_3,?y_3),+(?y,s(?y_2))), s(+(?x,?y_2)) = +(?x,+(0,s(?y_2))), s(+(s(+(?x,?y_5)),?y_2)) = +(?x,+(s(?y_5),s(?y_2))), s(+(?y,?y_2)) = +(0,+(?y,s(?y_2))), s(+(s(+(?x_7,?y)),?y_2)) = +(s(?x_7),+(?y,s(?y_2))), s(+(+(?y,?x),?y_2)) = +(?x,+(?y,s(?y_2))), +(?z,+(?x_1,+(?y_1,?y))) = +(+(?x_1,?y_1),+(?y,?z)), +(?z,?x) = +(?x,+(0,?z)), +(?z,s(+(?x,?y_3))) = +(?x,+(s(?y_3),?z)), +(?z,?y) = +(0,+(?y,?z)), +(?z,s(+(?x_5,?y))) = +(s(?x_5),+(?y,?z)), +(?z,+(?y,?x)) = +(?x,+(?y,?z)), +(?x,?y) = +(?x,+(?y,0)), s(+(+(?x,?y),?y_2)) = +(?x,+(?y,s(?y_2))), +(?z,+(?x,?y)) = +(?x,+(?y,?z)), +(+(?x_1,+(?y_1,?y)),?z) = +(+(?x_1,?y_1),+(?y,?z)), +(?x,?z) = +(?x,+(0,?z)), +(s(+(?x,?y_3)),?z) = +(?x,+(s(?y_3),?z)), +(?y,?z) = +(0,+(?y,?z)), +(s(+(?x_5,?y)),?z) = +(s(?x_5),+(?y,?z)), +(+(?y,?x),?z) = +(?x,+(?y,?z)), +(+(?x_2,+(?y_2,?y)),+(?z,?z_1)) = +(+(+(?x_2,?y_2),+(?y,?z)),?z_1), +(?x,+(?z,?z_1)) = +(+(?x,+(0,?z)),?z_1), +(s(+(?x,?y_4)),+(?z,?z_1)) = +(+(?x,+(s(?y_4),?z)),?z_1), +(?y,+(?z,?z_1)) = +(+(0,+(?y,?z)),?z_1), +(s(+(?x_6,?y)),+(?z,?z_1)) = +(+(s(?x_6),+(?y,?z)),?z_1), +(+(?y,?x),+(?z,?z_1)) = +(+(?x,+(?y,?z)),?z_1), +(+(?x,?y),+(?z,?z_1)) = +(+(?x,+(?y,?z)),?z_1) ] unknown Okui (Simultaneous CPs) unknown Strongly Depth-Preserving & Root-E-Closed/Non-E-Overlapping unknown Strongly Weight-Preserving & Root-E-Closed/Non-E-Overlapping check Locally Decreasing Diagrams by Rule Labelling... Critical Pair <+(?x,?z_6), +(?x,+(0,?z_6))> by Rules <0, 7> preceded by [(+,1)] joinable by a reduction of rules <[], [([(+,2)],2)]> Critical Pair <+(s(+(?x_1,?y_1)),?z_6), +(?x_1,+(s(?y_1),?z_6))> by Rules <1, 7> preceded by [(+,1)] joinable by a reduction of rules <[([],3),([(s,1)],7)], [([(+,2)],3),([],1)]> Critical Pair <+(?y_2,?z_6), +(0,+(?y_2,?z_6))> by Rules <2, 7> preceded by [(+,1)] joinable by a reduction of rules <[], [([],2)]> Critical Pair <+(s(+(?x_3,?y_3)),?z_6), +(s(?x_3),+(?y_3,?z_6))> by Rules <3, 7> preceded by [(+,1)] joinable by a reduction of rules <[([],3),([(s,1)],7)], [([],3)]> Critical Pair <+(+(?y_5,?x_5),?z_6), +(?x_5,+(?y_5,?z_6))> by Rules <6, 7> preceded by [(+,1)] joinable by a reduction of rules <[([(+,1)],6),([],7)], []> joinable by a reduction of rules <[([],7),([(+,2)],6)], [([],6),([],7)]> Critical Pair <+(+(?x,+(?y,?z)),?z_1), +(+(?x,?y),+(?z,?z_1))> by Rules <7, 7> preceded by [(+,1)] joinable by a reduction of rules <[([],7),([(+,2)],7)], [([],7)]> Critical Pair <0, 0> by Rules <2, 0> preceded by [] joinable by a reduction of rules <[], []> Critical Pair by Rules <3, 0> preceded by [] joinable by a reduction of rules <[([(s,1)],0)], []> Critical Pair <+(0,?x_5), ?x_5> by Rules <6, 0> preceded by [] joinable by a reduction of rules <[([],2)], []> Critical Pair <+(?x_6,+(?y_6,0)), +(?x_6,?y_6)> by Rules <7, 0> preceded by [] joinable by a reduction of rules <[([(+,2)],0)], []> Critical Pair by Rules <2, 1> preceded by [] joinable by a reduction of rules <[], [([(s,1)],2)]> Critical Pair by Rules <3, 1> preceded by [] joinable by a reduction of rules <[([(s,1)],1)], [([(s,1)],3)]> Critical Pair <+(s(?y_1),?x_5), s(+(?x_5,?y_1))> by Rules <6, 1> preceded by [] joinable by a reduction of rules <[([],3)], [([(s,1)],6)]> Critical Pair <+(?x_6,+(?y_6,s(?y_1))), s(+(+(?x_6,?y_6),?y_1))> by Rules <7, 1> preceded by [] joinable by a reduction of rules <[([(+,2)],1),([],1)], [([(s,1)],7)]> Critical Pair <+(?y_5,0), ?y_5> by Rules <6, 2> preceded by [] joinable by a reduction of rules <[([],0)], []> Critical Pair <+(?y_5,s(?x_3)), s(+(?x_3,?y_5))> by Rules <6, 3> preceded by [] joinable by a reduction of rules <[([],1)], [([(s,1)],6)]> Critical Pair <+(?x_6,+(?y_6,?z_6)), +(?z_6,+(?x_6,?y_6))> by Rules <7, 6> preceded by [] joinable by a reduction of rules <[], [([],6),([],7)]> unknown Diagram Decreasing check Non-Confluence... obtain 18 rules by 3 steps unfolding strenghten +(?x_9,0) and ?x_9 strenghten +(0,?x_5) and ?x_5 strenghten +(?x_12,?y_12) and +(?y_12,?x_12) strenghten +(?x_15,s(0)) and s(?x_15) strenghten +(s(0),?x_15) and s(?x_15) strenghten s(+(?x_3,0)) and s(?x_3) strenghten s(+(0,?y_1)) and s(?y_1) strenghten s(+(?x_3,?x_13)) and +(?x_13,s(?x_3)) strenghten s(+(?x_3,?x_14)) and +(s(?x_3),?x_14) strenghten s(+(?x_5,?y_1)) and +(s(?y_1),?x_5) strenghten s(+(?x_11,?y_1)) and +(?x_11,s(?y_1)) strenghten +(?x,+(0,?z_6)) and +(?x,?z_6) strenghten +(?x_6,+(?y_6,0)) and +(?x_6,?y_6) strenghten +(0,+(?x_9,?z_6)) and +(?x_9,?z_6) strenghten s(+(?x_3,s(0))) and s(s(?x_3)) strenghten +(?x_5,+(?y_5,?z_6)) and +(+(?y_5,?x_5),?z_6) strenghten +(?x_6,+(?y_6,?x_13)) and +(?x_13,+(?x_6,?y_6)) strenghten +(?x_6,+(?y_6,?x_14)) and +(+(?x_6,?y_6),?x_14) strenghten +(?z_6,+(?x_6,?y_6)) and +(?x_6,+(?y_6,?z_6)) strenghten s(+(s(?x_3),?y_1)) and s(+(?x_3,s(?y_1))) strenghten +(?x_6,+(?y_6,s(0))) and s(+(?x_6,?y_6)) strenghten +(?x_15,+(s(0),?z_6)) and +(s(?x_15),?z_6) strenghten +(?x_1,+(s(?y_1),?z_6)) and +(s(+(?x_1,?y_1)),?z_6) strenghten +(s(?x_3),+(?y_3,?z_6)) and +(s(+(?x_3,?y_3)),?z_6) obtain 100 candidates for checking non-joinability check by TCAP-Approximation (failure) check by Root-Approximation (failure) check by Ordering(rpo), check by Tree-Automata Approximation (failure) check by Interpretation(mod2) (failure) check by Descendants-Approximation, check by Ordering(poly) (failure) unknown Non-Confluence Check relative termination: [ +(?x,0) -> ?x, +(?x,s(?y)) -> s(+(?x,?y)), +(0,?y) -> ?y, +(s(?x),?y) -> s(+(?x,?y)), *(k,0) -> 0, *(k,s(?y)) -> +(k,*(k,?y)) ] [ +(?x,?y) -> +(?y,?x), +(+(?x,?y),?z) -> +(?x,+(?y,?z)) ] Polynomial Interpretation: *:= (2)+(1)*x1+(1)*x2 +:= (1)*x1+(1)*x1*x2+(1)*x2 0:= (8) k:= 0 s:= (8)+(8)*x1 retract +(?x,0) -> ?x retract +(0,?y) -> ?y retract *(k,0) -> 0 retract *(k,s(?y)) -> +(k,*(k,?y)) Polynomial Interpretation: *:= (2)*x1*x1+(1)*x2 +:= (2)+(2)*x1+(1)*x1*x2+(2)*x2 0:= (10) k:= 0 s:= (1)+(1)*x1 relatively terminating Huet (modulo AC) Direct Methods: CR Final result: CR 151.trs: Success(CR) (7317 msec.)