YES (ignored inputs)COMMENT from the collection of \cite{AT2012} Rewrite Rules: [ +(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)) ] Apply Direct Methods... Inner CPs: [ +(s(?x_4),?y_1) = s(+(s(?x_4),?y_1)), +(s(s(?x_5)),?y_1) = s(+(?x_5,?y_1)), +(?y,?z_2) = +(0,+(?y,?z_2)), +(s(+(?x_1,?y_1)),?z_2) = +(s(?x_1),+(?y_1,?z_2)), +(+(?y_3,?x_3),?z_2) = +(?x_3,+(?y_3,?z_2)), s(s(s(?x_5))) = s(?x_5), +(+(?x,+(?y,?z)),?z_1) = +(+(?x,?y),+(?z,?z_1)), s(s(?x)) = s(s(?x)) ] Outer CPs: [ ?y = +(?y,0), s(+(?x_1,?y_1)) = +(?y_1,s(?x_1)), +(?x_2,+(?y_2,?z_2)) = +(?z_2,+(?x_2,?y_2)), s(?x_4) = s(s(s(?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: [ +(?y,0) = ?y, +(0,+(?y,?z_3)) = +(?y,?z_3), +(?y,s(?x_5)) = s(+(s(?x_5),?y)), +(?y,s(s(?x))) = s(+(?x,?y)), +(?y,s(?x)) = s(+(?x,?y)), +(s(?x_5),?y) = s(+(s(?x_5),?y)), +(s(s(?x)),?y) = s(+(?x,?y)), +(s(?x_8),+(?y,?z_3)) = +(s(+(s(?x_8),?y)),?z_3), +(s(s(?x)),+(?y,?z_3)) = +(s(+(?x,?y)),?z_3), +(s(?x),+(?y,?z_3)) = +(s(+(?x,?y)),?z_3), +(?z,+(?x_1,+(?y_1,?y))) = +(+(?x_1,?y_1),+(?y,?z)), +(?z,?y) = +(0,+(?y,?z)), +(?z,s(+(?x_3,?y))) = +(s(?x_3),+(?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,?z) = +(0,+(?y,?z)), +(s(+(?x_3,?y)),?z) = +(s(?x_3),+(?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,+(?z,?z_1)) = +(+(0,+(?y,?z)),?z_1), +(s(+(?x_4,?y)),+(?z,?z_1)) = +(+(s(?x_4),+(?y,?z)),?z_1), +(+(?y,?x),+(?z,?z_1)) = +(+(?x,+(?y,?z)),?z_1), +(+(?x,?y),+(?z,?z_1)) = +(+(?x,+(?y,?z)),?z_1), ?y = +(?y,0), s(+(?x_2,?y)) = +(?y,s(?x_2)), +(?x_3,+(?y_3,?y)) = +(?y,+(?x_3,?y_3)), +(?x,+(?y,?z_4)) = +(+(?y,?x),?z_4), s(s(s(?x_1))) = s(s(?x_1)), s(s(s(s(?x)))) = s(?x), s(s(s(?x))) = s(?x), s(s(?x_1)) = s(s(?x_1)), s(s(?x_1)) = s(s(s(?x_1))), s(+(s(?x_4),?y_3)) = +(s(s(?x_4)),?y_3), s(+(s(s(?x)),?y_3)) = +(s(?x),?y_3), s(+(s(?x),?y_3)) = +(s(?x),?y_3), s(?x_5) = s(s(s(?x_5))), s(+(?x,?y_3)) = +(s(s(?x)),?y_3) ] 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 <+(s(?x_4),?y_1), s(+(s(?x_4),?y_1))> by Rules <4, 1> preceded by [(+,1)] joinable by a reduction of rules <[([(+,1)],5),([],1)], []> joinable by a reduction of rules <[([],1),([],5)], [([(s,1)],1)]> joinable by a reduction of rules <[([],1)], [([(s,1)],1),([],4)]> Critical Pair <+(s(s(?x_5)),?y_1), s(+(?x_5,?y_1))> by Rules <5, 1> preceded by [(+,1)] joinable by a reduction of rules <[([(+,1)],4),([],1)], []> joinable by a reduction of rules <[([],1),([(s,1)],1)], [([],5)]> Critical Pair <+(?y,?z_2), +(0,+(?y,?z_2))> by Rules <0, 2> preceded by [(+,1)] joinable by a reduction of rules <[], [([],0)]> Critical Pair <+(s(+(?x_1,?y_1)),?z_2), +(s(?x_1),+(?y_1,?z_2))> by Rules <1, 2> preceded by [(+,1)] joinable by a reduction of rules <[([],1),([(s,1)],2)], [([],1)]> Critical Pair <+(+(?y_3,?x_3),?z_2), +(?x_3,+(?y_3,?z_2))> by Rules <3, 2> preceded by [(+,1)] joinable by a reduction of rules <[([(+,1)],3),([],2)], []> joinable by a reduction of rules <[([],2),([(+,2)],3)], [([],3),([],2)]> Critical Pair by Rules <5, 4> preceded by [(s,1)] joinable by a reduction of rules <[([(s,1)],4)], [([],5)]> joinable by a reduction of rules <[([],4)], [([],5)]> 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 by Rules <4, 4> preceded by [(s,1)] joinable by a reduction of rules <[], []> Critical Pair <+(?y_3,0), ?y_3> by Rules <3, 0> preceded by [] joinable by a reduction of rules <[([],3),([],0)], []> Critical Pair <+(?y_3,s(?x_1)), s(+(?x_1,?y_3))> by Rules <3, 1> preceded by [] joinable by a reduction of rules <[([],3),([],1)], []> Critical Pair <+(?y_3,+(?x_2,?y_2)), +(?x_2,+(?y_2,?y_3))> by Rules <3, 2> preceded by [] joinable by a reduction of rules <[([],3),([],2)], []> Critical Pair by Rules <5, 4> preceded by [] joinable by a reduction of rules <[([(s,1)],4)], [([],5)]> joinable by a reduction of rules <[([],4)], [([],5)]> unknown Diagram Decreasing check Non-Confluence... obtain 16 rules by 3 steps unfolding strenghten +(?x_10,0) and ?x_10 strenghten +(0,?x_8) and ?x_8 strenghten s(s(?x_4)) and s(?x_4) strenghten s(+(?x_1,0)) and s(?x_1) strenghten s(s(s(?x_4))) and s(?x_4) strenghten s(+(?x_1,?y_3)) and +(?y_3,s(?x_1)) strenghten s(+(?x_6,?y_1)) and +(s(?x_6),?y_1) strenghten +(?x_2,+(?y_2,0)) and +(?x_2,?y_2) strenghten +(?x_8,+(0,?z_2)) and +(?x_8,?z_2) strenghten +(0,+(?x_10,?z_2)) and +(?x_10,?z_2) strenghten +(s(s(?x_5)),?y_1) and s(+(?x_5,?y_1)) strenghten s(+(s(?x_4),?y_1)) and +(s(?x_4),?y_1) strenghten +(?x_2,+(?y_2,?y_3)) and +(?y_3,+(?x_2,?y_2)) strenghten +(?x_3,+(?y_3,?z_2)) and +(+(?y_3,?x_3),?z_2) strenghten +(s(?x_1),+(?y_1,?z_2)) and +(s(+(?x_1,?y_1)),?z_2) 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, +(s(?x),?y) -> s(+(?x,?y)), s(s(?x)) -> s(?x), s(?x) -> s(s(?x)) ] [ +(+(?x,?y),?z) -> +(?x,+(?y,?z)), +(?x,?y) -> +(?y,?x) ] not relatively terminatiing unknown Huet (modulo AC) check by Reduction-Preserving Completion... STEP: 1 (parallel) S: [ +(0,?y) -> ?y, +(s(?x),?y) -> s(+(?x,?y)) ] P: [ +(+(?x,?y),?z) -> +(?x,+(?y,?z)), +(?x,?y) -> +(?y,?x), s(s(?x)) -> s(?x), s(?x) -> s(s(?x)) ] S: terminating CP(S,S): PCP_in(symP,S): <+(s(?x_5),?y), s(+(s(?x_5),?y))> --> => no <+(s(s(?x_4)),?y), s(+(?x_4,?y))> --> => no CP(S,symP): <+(?y,?z_1), +(0,+(?y,?z_1))> --> <+(?y,?z_1), +(?y,?z_1)> => yes <+(?y_1,?z_1), +(+(0,?y_1),?z_1)> --> <+(?y_1,?z_1), +(?y_1,?z_1)> => yes <+(?x_1,?y), +(+(?x_1,0),?y)> --> <+(?x_1,?y), +(+(?x_1,0),?y)> => no --> => no <+(s(+(?x,?y)),?z_1), +(s(?x),+(?y,?z_1))> --> => yes --> => yes <+(?x_1,s(+(?x,?y))), +(+(?x_1,s(?x)),?y)> --> <+(?x_1,s(+(?x,?y))), +(+(?x_1,s(?x)),?y)> => no --> => no check joinability condition: check modulo joinability of s(+(?x_5,?y)) and s(s(+(?x_5,?y))): joinable by {0} check modulo joinability of s(s(+(?x_4,?y))) and s(+(?x_4,?y)): joinable by {0} check modulo reachablity from +(?x_1,?y) to +(+(?x_1,0),?y): maybe not reachable check modulo reachablity from ?y to +(?y,0): maybe not reachable check modulo reachablity from +(?x_1,s(+(?x,?y))) to +(+(?x_1,s(?x)),?y): maybe not reachable check modulo reachablity from s(+(?x,?y)) to +(?y,s(?x)): maybe not reachable failed failure(Step 1) [ +(?y,0) -> ?y, +(?y,s(?x)) -> s(+(?x,?y)) ] Added S-Rules: [ +(?y,0) -> ?y, +(?y,s(?x)) -> s(+(?x,?y)) ] Added P-Rules: [ ] replace: +(s(?x),?y) -> s(+(?x,?y)) => +(s(?x),?y) -> s(+(?y,?x)) replace: +(s(?x),?y) -> s(+(?x,?y)) => +(s(?x),?y) -> s(s(+(?x,?y))) STEP: 2 (linear) S: [ +(0,?y) -> ?y, +(s(?x),?y) -> s(+(?x,?y)) ] P: [ +(+(?x,?y),?z) -> +(?x,+(?y,?z)), +(?x,?y) -> +(?y,?x), s(s(?x)) -> s(?x), s(?x) -> s(s(?x)) ] S: terminating CP(S,S): CP_in(symP,S): <+(s(s(?x)),?y_1), s(+(?x,?y_1))> --> => yes <+(s(?x),?y_1), s(+(s(?x),?y_1))> --> => yes CP(S,symP): <+(?y,?z_1), +(0,+(?y,?z_1))> --> <+(?y,?z_1), +(?y,?z_1)> => yes <+(?y_1,?z_1), +(+(0,?y_1),?z_1)> --> <+(?y_1,?z_1), +(?y_1,?z_1)> => yes <+(?x_1,?y), +(+(?x_1,0),?y)> --> <+(?x_1,?y), +(+(?x_1,0),?y)> => no --> => no <+(s(+(?x,?y)),?z_1), +(s(?x),+(?y,?z_1))> --> => yes --> => yes <+(?x_1,s(+(?x,?y))), +(+(?x_1,s(?x)),?y)> --> <+(?x_1,s(+(?x,?y))), +(+(?x_1,s(?x)),?y)> => no --> => no check joinability condition: check modulo reachablity from +(?x_1,?y) to +(+(?x_1,0),?y): maybe not reachable check modulo reachablity from ?y to +(?y,0): maybe not reachable check modulo reachablity from +(?x_1,s(+(?x,?y))) to +(+(?x_1,s(?x)),?y): maybe not reachable check modulo reachablity from s(+(?x,?y)) to +(?y,s(?x)): maybe not reachable failed failure(Step 2) [ +(?y,0) -> ?y, +(?y,s(?x)) -> s(+(?x,?y)) ] Added S-Rules: [ +(?y,0) -> ?y, +(?y,s(?x)) -> s(+(?x,?y)) ] Added P-Rules: [ ] replace: +(s(?x),?y) -> s(+(?x,?y)) => +(s(?x),?y) -> s(+(?y,?x)) replace: +(s(?x),?y) -> s(+(?x,?y)) => +(s(?x),?y) -> s(s(+(?x,?y))) STEP: 3 (relative) S: [ +(0,?y) -> ?y, +(s(?x),?y) -> s(+(?x,?y)) ] P: [ +(+(?x,?y),?z) -> +(?x,+(?y,?z)), +(?x,?y) -> +(?y,?x), s(s(?x)) -> s(?x), s(?x) -> s(s(?x)) ] Check relative termination: [ +(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)) ] Polynomial Interpretation: +:= (2)+(2)*x1+(1)*x1*x2+(2)*x2 0:= (12) s:= (1)*x1 retract +(0,?y) -> ?y Polynomial Interpretation: +:= (2)+(2)*x1+(1)*x1*x2+(2)*x2 0:= (10) s:= (1)+(1)*x1 relatively terminating S/P: relatively terminating check CP condition: failed failure(Step 3) STEP: 4 (parallel) S: [ +(0,?y) -> ?y, +(s(?x),?y) -> s(+(?x,?y)), +(?y,0) -> ?y, +(?y,s(?x)) -> s(+(?x,?y)) ] P: [ +(+(?x,?y),?z) -> +(?x,+(?y,?z)), +(?x,?y) -> +(?y,?x), s(s(?x)) -> s(?x), s(?x) -> s(s(?x)) ] S: terminating CP(S,S): <0, 0> --> <0, 0> => yes --> => yes --> => yes --> => yes PCP_in(symP,S): <+(s(?x_5),?y), s(+(s(?x_5),?y))> --> => no <+(s(s(?x_4)),?y), s(+(?x_4,?y))> --> => no <+(?y,s(?x_5)), s(+(s(?x_5),?y))> --> => no <+(?y,s(s(?x_4))), s(+(?x_4,?y))> --> => no CP(S,symP): <+(?y,?z_1), +(0,+(?y,?z_1))> --> <+(?y,?z_1), +(?y,?z_1)> => yes <+(?y_1,?z_1), +(+(0,?y_1),?z_1)> --> <+(?y_1,?z_1), +(?y_1,?z_1)> => yes <+(?x_1,?y), +(+(?x_1,0),?y)> --> <+(?x_1,?y), +(?x_1,?y)> => yes --> => yes <+(s(+(?x,?y)),?z_1), +(s(?x),+(?y,?z_1))> --> => yes --> => yes <+(?x_1,s(+(?x,?y))), +(+(?x_1,s(?x)),?y)> --> => no --> => yes <+(?x_1,?y_1), +(?x_1,+(?y_1,0))> --> <+(?x_1,?y_1), +(?x_1,?y_1)> => yes <+(?y,?z_1), +(?y,+(0,?z_1))> --> <+(?y,?z_1), +(?y,?z_1)> => yes <+(?x_1,?y), +(+(?x_1,?y),0)> --> <+(?x_1,?y), +(?x_1,?y)> => yes --> => yes --> => no <+(s(+(?x,?y)),?z_1), +(?y,+(s(?x),?z_1))> --> => no <+(?x_1,s(+(?x,?y))), +(+(?x_1,?y),s(?x))> --> => no --> => yes check joinability condition: check modulo joinability of s(+(?x_5,?y)) and s(s(+(?x_5,?y))): joinable by {0} check modulo joinability of s(s(+(?x_4,?y))) and s(+(?x_4,?y)): joinable by {0} check modulo joinability of s(+(?x_5,?y)) and s(s(+(?x_5,?y))): joinable by {0} check modulo joinability of s(s(+(?x_4,?y))) and s(+(?x_4,?y)): joinable by {0} check modulo joinability of s(+(+(?x,?y),?x_1)) and s(+(+(?x,?x_1),?y)): joinable by {3} check modulo joinability of s(+(?x,+(?x_1,?y_1))) and s(+(+(?x,?y_1),?x_1)): joinable by {3} check modulo joinability of s(+(+(?x,?y),?z_1)) and s(+(+(?x,?z_1),?y)): joinable by {3} check modulo joinability of s(+(+(?x,?y),?x_1)) and s(+(?x,+(?x_1,?y))): joinable by {3} success P': [ s(s(?x)) -> s(?x), +(+(?x,?y),?z) -> +(?x,+(?y,?z)) ] Check relative termination: [ +(0,?y) -> ?y, +(s(?x),?y) -> s(+(?x,?y)), +(?y,0) -> ?y, +(?y,s(?x)) -> s(+(?x,?y)) ] [ s(s(?x)) -> s(?x), +(+(?x,?y),?z) -> +(?x,+(?y,?z)) ] Polynomial Interpretation: +:= (1)*x1+(1)*x2 0:= (8) s:= (1)*x1 retract +(0,?y) -> ?y retract +(?y,0) -> ?y Polynomial Interpretation: +:= (1)+(2)*x1+(2)*x1*x2+(2)*x2 0:= (15) s:= (4)+(1)*x1 relatively terminating S/P': relatively terminating S: [ +(0,?y) -> ?y, +(s(?x),?y) -> s(+(?x,?y)), +(?y,0) -> ?y, +(?y,s(?x)) -> s(+(?x,?y)) ] P: [ +(+(?x,?y),?z) -> +(?x,+(?y,?z)), +(?x,?y) -> +(?y,?x), s(s(?x)) -> s(?x), s(?x) -> s(s(?x)) ] Success Reduction-Preserving Completion Direct Methods: CR Final result: CR 170.trs: Success(CR) (3017 msec.)