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)), dbl(0) -> 0, dbl(s(?x)) -> s(s(dbl(?x))), +(+(?x,?y),?z) -> +(?x,+(?y,?z)), +(?x,?y) -> +(?y,?x), dbl(+(?x,?y)) -> +(dbl(?x),dbl(?y)) ] Apply Direct Methods... Inner CPs: [ +(?x,?z_5) = +(?x,+(0,?z_5)), +(s(+(?x_1,?y_1)),?z_5) = +(?x_1,+(s(?y_1),?z_5)), +(?y_2,?z_5) = +(0,+(?y_2,?z_5)), +(s(+(?x_3,?y_3)),?z_5) = +(s(?x_3),+(?y_3,?z_5)), +(+(?y_6,?x_6),?z_5) = +(?x_6,+(?y_6,?z_5)), dbl(?x) = +(dbl(?x),dbl(0)), dbl(s(+(?x_1,?y_1))) = +(dbl(?x_1),dbl(s(?y_1))), dbl(?y_2) = +(dbl(0),dbl(?y_2)), dbl(s(+(?x_3,?y_3))) = +(dbl(s(?x_3)),dbl(?y_3)), dbl(+(?x_5,+(?y_5,?z_5))) = +(dbl(+(?x_5,?y_5)),dbl(?z_5)), dbl(+(?y_6,?x_6)) = +(dbl(?x_6),dbl(?y_6)), +(+(?x,+(?y,?z)),?z_1) = +(+(?x,?y),+(?z,?z_1)) ] Outer CPs: [ 0 = 0, s(?x_3) = s(+(?x_3,0)), +(?x_5,?y_5) = +(?x_5,+(?y_5,0)), ?x = +(0,?x), s(+(0,?y_1)) = s(?y_1), s(+(s(?x_3),?y_1)) = s(+(?x_3,s(?y_1))), s(+(+(?x_5,?y_5),?y_1)) = +(?x_5,+(?y_5,s(?y_1))), s(+(?x_1,?y_1)) = +(s(?y_1),?x_1), ?y_2 = +(?y_2,0), s(+(?x_3,?y_3)) = +(?y_3,s(?x_3)), +(?x_5,+(?y_5,?z_5)) = +(?z_5,+(?x_5,?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), +(?x_5,+(?y_5,0)) = +(?x_5,?y_5), +(0,?x) = ?x, +(?x,+(0,?z_6)) = +(?x,?z_6), +(dbl(?x),dbl(0)) = dbl(?x), s(?y) = s(+(0,?y)), s(+(?x_3,s(?y))) = s(+(s(?x_3),?y)), +(?x_5,+(?y_5,s(?y))) = s(+(+(?x_5,?y_5),?y)), +(s(?y),?x) = s(+(?x,?y)), +(?x,+(s(?y),?z_6)) = +(s(+(?x,?y)),?z_6), +(dbl(?x),dbl(s(?y))) = dbl(s(+(?x,?y))), s(+(0,?y_2)) = s(?y_2), +(?y,0) = ?y, +(0,+(?y,?z_6)) = +(?y,?z_6), +(dbl(0),dbl(?y)) = dbl(?y), 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_6)) = +(s(+(?x,?y)),?z_6), +(dbl(s(?x)),dbl(?y)) = dbl(s(+(?x,?y))), +(?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), +(dbl(+(?x_1,+(?y_1,?y))),dbl(?z)) = dbl(+(+(?x_1,?y_1),+(?y,?z))), +(dbl(?x),dbl(?z)) = dbl(+(?x,+(0,?z))), +(dbl(s(+(?x,?y_3))),dbl(?z)) = dbl(+(?x,+(s(?y_3),?z))), +(dbl(?y),dbl(?z)) = dbl(+(0,+(?y,?z))), +(dbl(s(+(?x_5,?y))),dbl(?z)) = dbl(+(s(?x_5),+(?y,?z))), +(dbl(+(?y,?x)),dbl(?z)) = dbl(+(?x,+(?y,?z))), +(+(?x,?y),+(?z,?z_1)) = +(+(?x,+(?y,?z)),?z_1), +(dbl(+(?x,?y)),dbl(?z)) = dbl(+(?x,+(?y,?z))), ?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), +(dbl(?x),dbl(?y)) = dbl(+(?y,?x)), dbl(?x) = +(dbl(?x),dbl(0)), dbl(s(+(?x,?y_3))) = +(dbl(?x),dbl(s(?y_3))), dbl(?y) = +(dbl(0),dbl(?y)), dbl(s(+(?x_5,?y))) = +(dbl(s(?x_5)),dbl(?y)), dbl(+(?x_7,+(?y_7,?y))) = +(dbl(+(?x_7,?y_7)),dbl(?y)), dbl(+(?y,?x)) = +(dbl(?x),dbl(?y)) ] 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_5), +(?x,+(0,?z_5))> by Rules <0, 6> preceded by [(+,1)] joinable by a reduction of rules <[], [([(+,2)],2)]> Critical Pair <+(s(+(?x_1,?y_1)),?z_5), +(?x_1,+(s(?y_1),?z_5))> by Rules <1, 6> preceded by [(+,1)] joinable by a reduction of rules <[([],3),([(s,1)],6)], [([(+,2)],3),([],1)]> Critical Pair <+(?y_2,?z_5), +(0,+(?y_2,?z_5))> by Rules <2, 6> preceded by [(+,1)] joinable by a reduction of rules <[], [([],2)]> Critical Pair <+(s(+(?x_3,?y_3)),?z_5), +(s(?x_3),+(?y_3,?z_5))> by Rules <3, 6> preceded by [(+,1)] joinable by a reduction of rules <[([],3),([(s,1)],6)], [([],3)]> Critical Pair <+(+(?y_6,?x_6),?z_5), +(?x_6,+(?y_6,?z_5))> by Rules <7, 6> preceded by [(+,1)] joinable by a reduction of rules <[([(+,1)],7),([],6)], []> joinable by a reduction of rules <[([],6),([(+,2)],7)], [([],7),([],6)]> Critical Pair by Rules <0, 8> preceded by [(dbl,1)] joinable by a reduction of rules <[], [([(+,2)],4),([],0)]> Critical Pair by Rules <1, 8> preceded by [(dbl,1)] joinable by a reduction of rules <[([],5),([(s,1),(s,1)],8)], [([(+,2)],5),([],1),([(s,1)],1)]> Critical Pair by Rules <2, 8> preceded by [(dbl,1)] joinable by a reduction of rules <[], [([(+,1)],4),([],2)]> Critical Pair by Rules <3, 8> preceded by [(dbl,1)] joinable by a reduction of rules <[([],5),([(s,1),(s,1)],8)], [([(+,1)],5),([],3),([(s,1)],3)]> Critical Pair by Rules <6, 8> preceded by [(dbl,1)] joinable by a reduction of rules <[([],8),([(+,2)],8)], [([(+,1)],8),([],6)]> Critical Pair by Rules <7, 8> preceded by [(dbl,1)] joinable by a reduction of rules <[([],8)], [([],7)]> Critical Pair <+(+(?x,+(?y,?z)),?z_1), +(+(?x,?y),+(?z,?z_1))> by Rules <6, 6> preceded by [(+,1)] joinable by a reduction of rules <[([],6),([(+,2)],6)], [([],6)]> 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 <+(?x_5,+(?y_5,0)), +(?x_5,?y_5)> by Rules <6, 0> preceded by [] joinable by a reduction of rules <[([(+,2)],0)], []> Critical Pair <+(0,?x_6), ?x_6> by Rules <7, 0> preceded by [] joinable by a reduction of rules <[([],2)], []> 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 <+(?x_5,+(?y_5,s(?y_1))), s(+(+(?x_5,?y_5),?y_1))> by Rules <6, 1> preceded by [] joinable by a reduction of rules <[([(+,2)],1),([],1)], [([(s,1)],6)]> Critical Pair <+(s(?y_1),?x_6), s(+(?x_6,?y_1))> by Rules <7, 1> preceded by [] joinable by a reduction of rules <[([],3)], [([(s,1)],7)]> Critical Pair <+(?y_6,0), ?y_6> by Rules <7, 2> preceded by [] joinable by a reduction of rules <[([],0)], []> Critical Pair <+(?y_6,s(?x_3)), s(+(?x_3,?y_6))> by Rules <7, 3> preceded by [] joinable by a reduction of rules <[([],1)], [([(s,1)],7)]> Critical Pair <+(?y_6,+(?x_5,?y_5)), +(?x_5,+(?y_5,?y_6))> by Rules <7, 6> preceded by [] joinable by a reduction of rules <[([],7),([],6)], []> unknown Diagram Decreasing check Non-Confluence... obtain 19 rules by 3 steps unfolding strenghten dbl(0) and 0 strenghten +(?x_10,0) and ?x_10 strenghten +(0,?x_6) and ?x_6 strenghten +(dbl(0),?x_12) and ?x_12 strenghten s(+(?x_3,0)) and s(?x_3) strenghten s(+(0,?y_1)) and s(?y_1) strenghten +(dbl(?x),dbl(0)) and dbl(?x) strenghten +(dbl(0),dbl(?x_10)) and dbl(?x_10) strenghten s(+(?x_3,dbl(0))) and s(?x_3) strenghten s(+(?x_3,?y_6)) and +(?y_6,s(?x_3)) strenghten s(+(?x_6,?y_1)) and +(s(?y_1),?x_6) strenghten +(?x,+(0,?z_5)) and +(?x,?z_5) strenghten +(?x_5,+(?y_5,0)) and +(?x_5,?y_5) strenghten +(0,+(?x_10,?z_5)) and +(?x_10,?z_5) strenghten +(dbl(?x_12),dbl(dbl(0))) and dbl(?x_12) strenghten +(dbl(?x_6),dbl(?y_6)) and dbl(+(?y_6,?x_6)) strenghten +(?x_5,+(?y_5,dbl(0))) and +(?x_5,?y_5) strenghten +(?x_12,+(dbl(0),?z_5)) and +(?x_12,?z_5) strenghten +(?x_5,+(?y_5,?y_6)) and +(?y_6,+(?x_5,?y_5)) strenghten +(?x_6,+(?y_6,?z_5)) and +(+(?y_6,?x_6),?z_5) strenghten s(+(s(?x_3),?y_1)) and s(+(?x_3,s(?y_1))) strenghten +(dbl(?x_1),dbl(s(?y_1))) and dbl(s(+(?x_1,?y_1))) strenghten +(dbl(s(?x_3)),dbl(?y_3)) and dbl(s(+(?x_3,?y_3))) strenghten +(?x_1,+(s(?y_1),?z_5)) and +(s(+(?x_1,?y_1)),?z_5) strenghten +(s(?x_3),+(?y_3,?z_5)) and +(s(+(?x_3,?y_3)),?z_5) 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)), dbl(0) -> 0, dbl(s(?x)) -> s(s(dbl(?x))), dbl(+(?x,?y)) -> +(dbl(?x),dbl(?y)) ] [ +(+(?x,?y),?z) -> +(?x,+(?y,?z)), +(?x,?y) -> +(?y,?x) ] Polynomial Interpretation: +:= (1)*x1+(1)*x2 0:= (8) s:= (1)*x1 dbl:= (7)+(1)*x1 retract +(?x,0) -> ?x retract +(0,?y) -> ?y retract dbl(0) -> 0 Polynomial Interpretation: +:= (1)*x1+(1)*x2 0:= (2) s:= (1)+(1)*x1 dbl:= (1)+(3)*x1+(5)*x1*x1 retract +(?x,0) -> ?x retract +(0,?y) -> ?y retract dbl(0) -> 0 retract dbl(s(?x)) -> s(s(dbl(?x))) Polynomial Interpretation: +:= (3)+(1)*x1+(1)*x2 0:= (2) s:= (1)*x1 dbl:= (5)+(8)*x1+(2)*x1*x1 retract +(?x,0) -> ?x retract +(0,?y) -> ?y retract dbl(0) -> 0 retract dbl(s(?x)) -> s(s(dbl(?x))) retract dbl(+(?x,?y)) -> +(dbl(?x),dbl(?y)) Polynomial Interpretation: +:= (1)+(2)*x1+(2)*x1*x2+(2)*x2 0:= 0 s:= (2)+(1)*x1 dbl:= (2)*x1 relatively terminating Huet (modulo AC) Direct Methods: CR Final result: CR 189.trs: Success(CR) (6421 msec.)