YES (ignored inputs)COMMENT reduction failed Rewrite Rules: [ +(0,?y) -> ?y, +(s(?x),?y) -> s(+(?x,?y)), +(?x,0) -> ?x, +(?x,s(?y)) -> s(+(?x,?y)) ] Apply Direct Methods... Inner CPs: [ ] Outer CPs: [ 0 = 0, s(?y_3) = s(+(0,?y_3)), s(+(?x_1,0)) = s(?x_1), s(+(?x_1,s(?y_3))) = s(+(s(?x_1),?y_3)) ] Overlay, check Innermost Termination... Innermost Terminating (hence Terminating), WCR Knuth & Bendix Direct Methods: CR Combined result: CR /tmp/fileUbu9wy.trs: Success(CR) (3 msec.)