YES (ignored inputs)COMMENT from the collection of \cite{AT2012} Rewrite Rules: [ +(0,?y) -> ?y, +(?x,0) -> ?x, +(s(?x),?y) -> s(+(?y,?x)), +(?x,s(?y)) -> s(+(?y,?x)), +(?x,+(?y,?z)) -> +(+(?x,?y),?z), +(?x,?y) -> +(?y,?x) ] Apply Direct Methods... Inner CPs: [ +(?x_4,?y) = +(+(?x_4,0),?y), +(?x_4,?x_1) = +(+(?x_4,?x_1),0), +(?x_4,s(+(?y_2,?x_2))) = +(+(?x_4,s(?x_2)),?y_2), +(?x_4,s(+(?y_3,?x_3))) = +(+(?x_4,?x_3),s(?y_3)), +(?x_4,+(?y_5,?x_5)) = +(+(?x_4,?x_5),?y_5), +(?x_1,+(+(?x,?y),?z)) = +(+(?x_1,?x),+(?y,?z)) ] Outer CPs: [ 0 = 0, s(?y_3) = s(+(?y_3,0)), +(?y_4,?z_4) = +(+(0,?y_4),?z_4), ?y = +(?y,0), s(?x_2) = s(+(0,?x_2)), ?x_1 = +(0,?x_1), s(+(s(?y_3),?x_2)) = s(+(?y_3,s(?x_2))), s(+(+(?y_4,?z_4),?x_2)) = +(+(s(?x_2),?y_4),?z_4), s(+(?y_2,?x_2)) = +(?y_2,s(?x_2)), s(+(?y_3,?x_3)) = +(s(?y_3),?x_3), +(+(?x_4,?y_4),?z_4) = +(+(?y_4,?z_4),?x_4) ] 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(+(?y_3,0)) = s(?y_3), +(+(0,?y_4),?z_4) = +(?y_4,?z_4), +(?y,0) = ?y, +(+(?x_5,0),?y) = +(?x_5,?y), s(+(0,?x_2)) = s(?x_2), +(0,?x) = ?x, +(+(?x_5,?x),0) = +(?x_5,?x), s(?x) = s(+(0,?x)), s(+(?y_3,s(?x))) = s(+(s(?y_3),?x)), +(+(s(?x),?y_4),?z_4) = s(+(+(?y_4,?z_4),?x)), +(?y,s(?x)) = s(+(?y,?x)), +(+(?x_5,s(?x)),?y) = +(?x_5,s(+(?y,?x))), s(?y) = s(+(?y,0)), s(+(s(?y),?x_3)) = s(+(?y,s(?x_3))), +(s(?y),?x) = s(+(?y,?x)), +(+(?x_5,?x),s(?y)) = +(?x_5,s(+(?y,?x))), +(+(?y,?y_1),?z_1) = +(+(0,?y),+(?y_1,?z_1)), ?z = +(+(0,0),?z), ?y = +(+(0,?y),0), s(+(?z,?x_4)) = +(+(0,s(?x_4)),?z), s(+(?y_5,?y)) = +(+(0,?y),s(?y_5)), +(?z,?y) = +(+(0,?y),?z), s(+(+(+(?y,?y_4),?z_4),?x_3)) = +(+(s(?x_3),?y),+(?y_4,?z_4)), s(+(?z,?x_3)) = +(+(s(?x_3),0),?z), s(+(?y,?x_3)) = +(+(s(?x_3),?y),0), s(+(s(+(?z,?x_7)),?x_3)) = +(+(s(?x_3),s(?x_7)),?z), s(+(s(+(?y_8,?y)),?x_3)) = +(+(s(?x_3),?y),s(?y_8)), s(+(+(?z,?y),?x_3)) = +(+(s(?x_3),?y),?z), +(+(+(?y,?y_1),?z_1),?x) = +(+(?x,?y),+(?y_1,?z_1)), +(?z,?x) = +(+(?x,0),?z), +(?y,?x) = +(+(?x,?y),0), +(s(+(?z,?x_4)),?x) = +(+(?x,s(?x_4)),?z), +(s(+(?y_5,?y)),?x) = +(+(?x,?y),s(?y_5)), +(+(?z,?y),?x) = +(+(?x,?y),?z), +(?y,?z) = +(+(0,?y),?z), s(+(+(?y,?z),?x_3)) = +(+(s(?x_3),?y),?z), +(+(?y,?z),?x) = +(+(?x,?y),?z), +(?x,+(+(?y,?y_1),?z_1)) = +(+(?x,?y),+(?y_1,?z_1)), +(?x,?z) = +(+(?x,0),?z), +(?x,?y) = +(+(?x,?y),0), +(?x,s(+(?z,?x_4))) = +(+(?x,s(?x_4)),?z), +(?x,s(+(?y_5,?y))) = +(+(?x,?y),s(?y_5)), +(?x,+(?z,?y)) = +(+(?x,?y),?z), +(+(?x_1,?x),+(+(?y,?y_2),?z_2)) = +(?x_1,+(+(?x,?y),+(?y_2,?z_2))), +(+(?x_1,?x),?z) = +(?x_1,+(+(?x,0),?z)), +(+(?x_1,?x),?y) = +(?x_1,+(+(?x,?y),0)), +(+(?x_1,?x),s(+(?z,?x_5))) = +(?x_1,+(+(?x,s(?x_5)),?z)), +(+(?x_1,?x),s(+(?y_6,?y))) = +(?x_1,+(+(?x,?y),s(?y_6))), +(+(?x_1,?x),+(?z,?y)) = +(?x_1,+(+(?x,?y),?z)), +(+(?x_1,?x),+(?y,?z)) = +(?x_1,+(+(?x,?y),?z)), ?y = +(?y,0), ?x = +(0,?x), s(+(?y,?x_3)) = +(?y,s(?x_3)), s(+(?y_4,?x)) = +(s(?y_4),?x), +(+(?x,?y_5),?z_5) = +(+(?y_5,?z_5),?x), +(+(?x_6,?x),?y) = +(?x_6,+(?y,?x)) ] 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_4,?y), +(+(?x_4,0),?y)> by Rules <0, 4> preceded by [(+,2)] joinable by a reduction of rules <[], [([(+,1)],1)]> Critical Pair <+(?x_4,?x_1), +(+(?x_4,?x_1),0)> by Rules <1, 4> preceded by [(+,2)] joinable by a reduction of rules <[], [([],1)]> Critical Pair <+(?x_4,s(+(?y_2,?x_2))), +(+(?x_4,s(?x_2)),?y_2)> by Rules <2, 4> preceded by [(+,2)] joinable by a reduction of rules <[([],3)], [([(+,1)],3),([],2),([(s,1)],4)]> joinable by a reduction of rules <[([(+,2),(s,1)],5),([],3),([(s,1),(+,1)],5)], [([(+,1)],3),([],2),([(s,1)],4)]> joinable by a reduction of rules <[([],5),([],2),([(s,1)],5)], [([(+,1)],3),([],2),([(s,1)],4)]> Critical Pair <+(?x_4,s(+(?y_3,?x_3))), +(+(?x_4,?x_3),s(?y_3))> by Rules <3, 4> preceded by [(+,2)] joinable by a reduction of rules <[([],3)], [([(+,1)],5),([],3),([(s,1)],4)]> joinable by a reduction of rules <[([],3)], [([],3),([(s,1),(+,2)],5),([(s,1)],4)]> joinable by a reduction of rules <[([(+,2),(s,1)],5),([],3),([(s,1),(+,1)],5)], [([(+,1)],5),([],3),([(s,1)],4)]> joinable by a reduction of rules <[([(+,2),(s,1)],5),([],3),([(s,1),(+,1)],5)], [([],3),([(s,1),(+,2)],5),([(s,1)],4)]> joinable by a reduction of rules <[([],5),([],2),([(s,1)],5)], [([(+,1)],5),([],3),([(s,1)],4)]> joinable by a reduction of rules <[([],5),([],2),([(s,1)],5)], [([],3),([(s,1),(+,2)],5),([(s,1)],4)]> joinable by a reduction of rules <[([],5),([],2),([(s,1)],4)], [([],3),([(s,1)],4),([(s,1),(+,1)],5)]> joinable by a reduction of rules <[([],3),([(s,1)],5),([(s,1)],4)], [([],3),([(s,1)],4),([(s,1),(+,1)],5)]> Critical Pair <+(?x_4,+(?y_5,?x_5)), +(+(?x_4,?x_5),?y_5)> by Rules <5, 4> preceded by [(+,2)] joinable by a reduction of rules <[([(+,2)],5),([],4)], []> joinable by a reduction of rules <[([],4),([(+,1)],5)], [([],5),([],4)]> Critical Pair <+(?x_1,+(+(?x,?y),?z)), +(+(?x_1,?x),+(?y,?z))> by Rules <4, 4> preceded by [(+,2)] joinable by a reduction of rules <[([],4),([(+,1)],4)], [([],4)]> Critical Pair <0, 0> by Rules <1, 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)],1)], []> Critical Pair <+(+(0,?y_4),?z_4), +(?y_4,?z_4)> by Rules <4, 0> preceded by [] joinable by a reduction of rules <[([(+,1)],0)], []> Critical Pair <+(?y_5,0), ?y_5> by Rules <5, 0> preceded by [] joinable by a reduction of rules <[([],1)], []> Critical Pair by Rules <2, 1> preceded by [] joinable by a reduction of rules <[([(s,1)],0)], []> Critical Pair <+(0,?x_5), ?x_5> by Rules <5, 1> preceded by [] joinable by a reduction of rules <[([],0)], []> Critical Pair by Rules <3, 2> preceded by [] joinable by a reduction of rules <[([(s,1)],3)], [([(s,1)],2)]> Critical Pair <+(+(s(?x_2),?y_4),?z_4), s(+(+(?y_4,?z_4),?x_2))> by Rules <4, 2> preceded by [] joinable by a reduction of rules <[([(+,1)],2),([],2),([(s,1)],4)], [([(s,1),(+,1)],5)]> joinable by a reduction of rules <[([(+,1)],5),([(+,1)],3),([],2)], [([(s,1)],5),([(s,1)],4),([(s,1)],5)]> joinable by a reduction of rules <[([(+,1)],2),([(+,1),(s,1)],5),([],2)], [([(s,1)],5),([(s,1)],4),([(s,1)],5)]> joinable by a reduction of rules <[([(+,1)],2),([],5),([],3)], [([(s,1)],5),([(s,1)],4),([(s,1),(+,1)],5)]> joinable by a reduction of rules <[([(+,1)],2),([],2),([(s,1),(+,2)],5)], [([(s,1)],5),([(s,1)],4),([(s,1)],5)]> joinable by a reduction of rules <[([(+,1)],2),([],2),([(s,1)],5)], [([(s,1)],5),([(s,1)],4),([(s,1),(+,1)],5)]> joinable by a reduction of rules <[([(+,1)],2),([],2),([(s,1)],4)], [([(s,1)],5),([(s,1),(+,2)],5),([(s,1)],5)]> joinable by a reduction of rules <[([],5),([(+,2)],2),([],3)], [([(s,1)],5),([(s,1)],4),([(s,1),(+,1)],5)]> Critical Pair <+(?y_5,s(?x_2)), s(+(?y_5,?x_2))> by Rules <5, 2> preceded by [] joinable by a reduction of rules <[([],3)], [([(s,1)],5)]> Critical Pair <+(s(?y_3),?x_5), s(+(?y_3,?x_5))> by Rules <5, 3> preceded by [] joinable by a reduction of rules <[([],2)], [([(s,1)],5)]> Critical Pair <+(+(?y_4,?z_4),?x_5), +(+(?x_5,?y_4),?z_4)> by Rules <5, 4> preceded by [] joinable by a reduction of rules <[([],5),([],4)], []> unknown Diagram Decreasing check Non-Confluence... obtain 16 rules by 3 steps unfolding strenghten +(?x_8,0) and ?x_8 strenghten +(0,?x_5) and ?x_5 strenghten +(?x_11,?y_11) and +(?y_11,?x_11) strenghten +(?x_14,s(0)) and s(?x_14) strenghten +(s(0),?x_14) and s(?x_14) strenghten s(+(?y_3,0)) and s(?y_3) strenghten s(+(0,?x_2)) and s(?x_2) strenghten s(+(?x_12,?x_2)) and +(?x_12,s(?x_2)) strenghten s(+(?x_13,?x_2)) and +(s(?x_2),?x_13) strenghten s(+(?y_3,?x_5)) and +(s(?y_3),?x_5) strenghten s(+(?y_3,?x_10)) and +(?x_10,s(?y_3)) strenghten +(+(?x_4,?x_1),0) and +(?x_4,?x_1) strenghten +(+(?x_4,0),?x_8) and +(?x_4,?x_8) strenghten +(+(0,?y_4),?z_4) and +(?y_4,?z_4) strenghten s(+(s(0),?x_2)) and s(s(?x_2)) strenghten +(+(?x_4,?x_5),?y_5) and +(?x_4,+(?y_5,?x_5)) strenghten +(+(?x_4,?x_10),?y_10) and +(?x_4,+(?x_10,?y_10)) strenghten +(+(?x_5,?y_4),?z_4) and +(+(?y_4,?z_4),?x_5) strenghten s(+(s(?y_3),?x_2)) and s(+(?y_3,s(?x_2))) strenghten +(+(?x_4,?x_14),s(0)) and +(?x_4,s(?x_14)) strenghten +(+(?x_4,?x_3),s(?y_3)) and +(?x_4,s(+(?y_3,?x_3))) strenghten +(+(?x_4,s(?x_2)),?y_2) and +(?x_4,s(+(?y_2,?x_2))) strenghten s(+(+(?y_4,?z_4),?x_2)) and +(+(s(?x_2),?y_4),?z_4) 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: [ +(0,?y) -> ?y, +(?x,0) -> ?x, +(s(?x),?y) -> s(+(?y,?x)), +(?x,s(?y)) -> s(+(?y,?x)) ] [ +(?x,+(?y,?z)) -> +(+(?x,?y),?z), +(?x,?y) -> +(?y,?x) ] Polynomial Interpretation: +:= (1)*x1+(1)*x2 0:= (8) s:= (1)*x1 retract +(0,?y) -> ?y retract +(?x,0) -> ?x Polynomial Interpretation: +:= (1)+(2)*x1+(2)*x1*x2+(2)*x2 0:= 0 s:= (4)+(4)*x1 relatively terminating Huet (modulo AC) Direct Methods: CR Final result: CR 191.trs: Success(CR) (3837 msec.)