YES (ignored inputs)COMMENT from the collection of \cite{AT2012} Rewrite Rules: [ -(+(?x,?y)) -> +(-(?x),-(?y)), +(?x,?y) -> +(?y,?x), +(+(?x,?y),?z) -> +(?x,+(?y,?z)) ] Apply Direct Methods... Inner CPs: [ -(+(?y_1,?x_1)) = +(-(?x_1),-(?y_1)), -(+(?x_2,+(?y_2,?z_2))) = +(-(+(?x_2,?y_2)),-(?z_2)), +(+(?y_1,?x_1),?z_2) = +(?x_1,+(?y_1,?z_2)), +(+(?x,+(?y,?z)),?z_1) = +(+(?x,?y),+(?z,?z_1)) ] Outer CPs: [ +(?y_1,+(?x_2,?y_2)) = +(?x_2,+(?y_2,?y_1)) ] 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: [ -(+(?y,?x)) = +(-(?x),-(?y)), -(+(?x_3,+(?y_3,?y))) = +(-(+(?x_3,?y_3)),-(?y)), +(?x_2,+(?y_2,?y)) = +(?y,+(?x_2,?y_2)), +(-(?x),-(?y)) = -(+(?y,?x)), +(?x,+(?y,?z_3)) = +(+(?y,?x),?z_3), +(?z,+(?x_1,+(?y_1,?y))) = +(+(?x_1,?y_1),+(?y,?z)), +(?z,+(?y,?x)) = +(?x,+(?y,?z)), +(?z,+(?x,?y)) = +(?x,+(?y,?z)), +(+(?x_1,+(?y_1,?y)),?z) = +(+(?x_1,?y_1),+(?y,?z)), +(+(?y,?x),?z) = +(?x,+(?y,?z)), +(+(?x_2,+(?y_2,?y)),+(?z,?z_1)) = +(+(+(?x_2,?y_2),+(?y,?z)),?z_1), +(+(?y,?x),+(?z,?z_1)) = +(+(?x,+(?y,?z)),?z_1), +(-(+(?x_1,+(?y_1,?y))),-(?z)) = -(+(+(?x_1,?y_1),+(?y,?z))), +(-(+(?y,?x)),-(?z)) = -(+(?x,+(?y,?z))), +(+(?x,?y),+(?z,?z_1)) = +(+(?x,+(?y,?z)),?z_1), +(-(+(?x,?y)),-(?z)) = -(+(?x,+(?y,?z))) ] 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 <-(+(?y_1,?x_1)), +(-(?x_1),-(?y_1))> by Rules <1, 0> preceded by [(-,1)] joinable by a reduction of rules <[([],0)], [([],1)]> Critical Pair <-(+(?x_2,+(?y_2,?z_2))), +(-(+(?x_2,?y_2)),-(?z_2))> by Rules <2, 0> preceded by [(-,1)] joinable by a reduction of rules <[([],0),([(+,2)],0)], [([(+,1)],0),([],2)]> Critical Pair <+(+(?y_1,?x_1),?z_2), +(?x_1,+(?y_1,?z_2))> by Rules <1, 2> preceded by [(+,1)] joinable by a reduction of rules <[([(+,1)],1),([],2)], []> joinable by a reduction of rules <[([],2),([(+,2)],1)], [([],1),([],2)]> Critical Pair <+(+(?x,+(?y,?z)),?z_1), +(+(?x,?y),+(?z,?z_1))> by Rules <2, 2> preceded by [(+,1)] joinable by a reduction of rules <[([],2),([(+,2)],2)], [([],2)]> Critical Pair <+(?x_2,+(?y_2,?z_2)), +(?z_2,+(?x_2,?y_2))> by Rules <2, 1> preceded by [] joinable by a reduction of rules <[], [([],1),([],2)]> unknown Diagram Decreasing check Non-Confluence... obtain 13 rules by 3 steps unfolding strenghten +(?x_4,?y_4) and +(?y_4,?x_4) strenghten +(-(?x_1),-(?y_1)) and -(+(?y_1,?x_1)) strenghten +(-(?x_3),-(?y_3)) and -(+(?x_3,?y_3)) strenghten +(?x_1,+(?y_1,?z_2)) and +(+(?y_1,?x_1),?z_2) strenghten +(?x_2,+(?y_2,?x_5)) and +(?x_5,+(?x_2,?y_2)) strenghten +(?x_2,+(?y_2,?x_6)) and +(+(?x_2,?y_2),?x_6) strenghten +(?z_2,+(?x_2,?y_2)) and +(?x_2,+(?y_2,?z_2)) strenghten +(-(?x_8),-(?y_8)) and +(-(?y_8),-(?x_8)) strenghten +(-(?z_2),-(+(?x_2,?y_2))) and -(+(?x_2,+(?y_2,?z_2))) strenghten +(-(+(?x_2,?y_2)),-(?z_2)) and -(+(?x_2,+(?y_2,?z_2))) strenghten +(+(?x,?y),+(?z,?z_1)) and +(+(?x,+(?y,?z)),?z_1) 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,?y)) -> +(-(?x),-(?y)) ] [ +(?x,?y) -> +(?y,?x), +(+(?x,?y),?z) -> +(?x,+(?y,?z)) ] Polynomial Interpretation: +:= (2)+(1)*x1+(1)*x2 -:= (2)+(4)*x1+(8)*x1*x1 relatively terminating Huet (modulo AC) Direct Methods: CR Final result: CR 147.trs: Success(CR) (9967 msec.)