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)), inc(?x) -> s(?x), +(?x,?y) -> +(?y,?x), inc(+(?x,?y)) -> +(inc(?x),?y) ] Apply Direct Methods... Inner CPs: [ inc(?x) = +(inc(?x),0), inc(s(+(?x_1,?y_1))) = +(inc(?x_1),s(?y_1)), inc(?y_2) = +(inc(0),?y_2), inc(s(+(?x_3,?y_3))) = +(inc(s(?x_3)),?y_3), inc(+(?y_5,?x_5)) = +(inc(?x_5),?y_5) ] Outer CPs: [ 0 = 0, s(?x_3) = s(+(?x_3,0)), ?x = +(0,?x), s(+(0,?y_1)) = s(?y_1), s(+(s(?x_3),?y_1)) = s(+(?x_3,s(?y_1))), s(+(?x_1,?y_1)) = +(s(?y_1),?x_1), ?y_2 = +(?y_2,0), s(+(?x_3,?y_3)) = +(?y_3,s(?x_3)), s(+(?x_6,?y_6)) = +(inc(?x_6),?y_6) ] 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, +(inc(?x),0) = inc(?x), s(?y) = s(+(0,?y)), s(+(?x_3,s(?y))) = s(+(s(?x_3),?y)), +(s(?y),?x) = s(+(?x,?y)), +(inc(?x),s(?y)) = inc(s(+(?x,?y))), s(+(0,?y_2)) = s(?y_2), +(?y,0) = ?y, +(inc(0),?y) = inc(?y), s(?x) = s(+(?x,0)), s(+(s(?x),?y_2)) = s(+(?x,s(?y_2))), +(?y,s(?x)) = s(+(?x,?y)), +(inc(s(?x)),?y) = inc(s(+(?x,?y))), +(inc(?x_6),?y_6) = s(+(?x_6,?y_6)), ?x = +(0,?x), s(+(?x,?y_2)) = +(s(?y_2),?x), ?y = +(?y,0), s(+(?x_4,?y)) = +(?y,s(?x_4)), +(inc(?x),?y) = inc(+(?y,?x)), s(?x) = +(inc(?x),0), s(s(+(?x,?y_3))) = +(inc(?x),s(?y_3)), s(?y) = +(inc(0),?y), s(s(+(?x_5,?y))) = +(inc(s(?x_5)),?y), s(+(?y,?x)) = +(inc(?x),?y), s(+(?x,?y)) = +(inc(?x),?y), inc(?x) = +(inc(?x),0), inc(s(+(?x,?y_3))) = +(inc(?x),s(?y_3)), inc(?y) = +(inc(0),?y), inc(s(+(?x_5,?y))) = +(inc(s(?x_5)),?y), inc(+(?y,?x)) = +(inc(?x),?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 by Rules <0, 6> preceded by [(inc,1)] joinable by a reduction of rules <[], [([],0)]> Critical Pair by Rules <1, 6> preceded by [(inc,1)] joinable by a reduction of rules <[([],4)], [([(+,1)],4),([],3),([(s,1)],1)]> joinable by a reduction of rules <[([],4)], [([(+,1)],4),([],1),([(s,1)],3)]> joinable by a reduction of rules <[([],4)], [([],1),([(s,1),(+,1)],4),([(s,1)],3)]> joinable by a reduction of rules <[([(inc,1),(s,1)],5),([],4),([(s,1),(s,1)],5)], [([(+,1)],4),([],3),([(s,1)],1)]> joinable by a reduction of rules <[([(inc,1),(s,1)],5),([],4),([(s,1),(s,1)],5)], [([(+,1)],4),([],1),([(s,1)],3)]> joinable by a reduction of rules <[([(inc,1),(s,1)],5),([],4),([(s,1),(s,1)],5)], [([],1),([(s,1),(+,1)],4),([(s,1)],3)]> Critical Pair by Rules <2, 6> preceded by [(inc,1)] joinable by a reduction of rules <[([],4)], [([(+,1)],4),([],3),([(s,1)],2)]> Critical Pair by Rules <3, 6> preceded by [(inc,1)] joinable by a reduction of rules <[([],4)], [([(+,1)],4),([],3),([(s,1)],3)]> joinable by a reduction of rules <[([(inc,1),(s,1)],5),([],4),([(s,1),(s,1)],5)], [([(+,1)],4),([],3),([(s,1)],3)]> Critical Pair by Rules <5, 6> preceded by [(inc,1)] joinable by a reduction of rules <[([(inc,1)],5),([],6)], []> joinable by a reduction of rules <[([(inc,1)],5),([],4)], [([(+,1)],4),([],3)]> joinable by a reduction of rules <[([],4),([(s,1)],5)], [([(+,1)],4),([],3)]> 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 <5, 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 <+(s(?y_1),?x_5), s(+(?x_5,?y_1))> by Rules <5, 1> preceded by [] joinable by a reduction of rules <[([],3)], [([(s,1)],5)]> Critical Pair <+(?y_5,0), ?y_5> by Rules <5, 2> preceded by [] joinable by a reduction of rules <[([],0)], []> Critical Pair <+(?y_5,s(?x_3)), s(+(?x_3,?y_5))> by Rules <5, 3> preceded by [] joinable by a reduction of rules <[([],1)], [([(s,1)],5)]> Critical Pair <+(inc(?x_6),?y_6), s(+(?x_6,?y_6))> by Rules <6, 4> preceded by [] joinable by a reduction of rules <[([(+,1)],4),([],3)], []> Satisfiable by 6>2,1>3>4,7>5; +(1,1)s(0)inc(2); 2>6>7>1>3>5>4 Diagram Decreasing Direct Methods: CR Final result: CR 159.trs: Success(CR) (8 msec.)