YES 1 decompositions #0 ----------- 1: +(x,0()) -> x 2: +(x,s(y)) -> s(+(x,y)) 3: +(x,p(y)) -> p(+(x,y)) 4: +(0(),y) -> y 5: +(s(x),y) -> s(+(x,y)) 6: +(p(x),y) -> p(+(x,y)) 7: s(p(x)) -> x 8: p(s(x)) -> x 9: -(0()) -> 0() 10: -(s(x)) -> p(-(x)) 11: -(p(x)) -> s(-(x)) 12: +(+(x,y),z) -> +(x,+(y,z)) 13: +(x,+(y,z)) -> +(+(x,y),z) 14: -(+(x,y)) -> +(-(x),-(y)) @Jouannaud and Kirchner's criterion --- R 1: +(x,0()) -> x 2: +(x,s(y)) -> s(+(x,y)) 3: +(x,p(y)) -> p(+(x,y)) 4: +(0(),y) -> y 5: +(s(x),y) -> s(+(x,y)) 6: +(p(x),y) -> p(+(x,y)) 7: s(p(x)) -> x 8: p(s(x)) -> x 9: -(0()) -> 0() 10: -(s(x)) -> p(-(x)) 11: -(p(x)) -> s(-(x)) 12: +(+(x,y),z) -> +(x,+(y,z)) 13: +(x,+(y,z)) -> +(+(x,y),z) 14: -(+(x,y)) -> +(-(x),-(y)) --- S 1: +(x,0()) -> x 2: +(x,s(y)) -> s(+(x,y)) 3: +(x,p(y)) -> p(+(x,y)) 4: +(0(),y) -> y 5: +(s(x),y) -> s(+(x,y)) 6: +(p(x),y) -> p(+(x,y)) 7: s(p(x)) -> x 8: p(s(x)) -> x 9: -(0()) -> 0() 10: -(s(x)) -> p(-(x)) 11: -(p(x)) -> s(-(x)) 12: +(+(x,y),z) -> +(x,+(y,z)) 13: +(x,+(y,z)) -> +(+(x,y),z) 14: -(+(x,y)) -> +(-(x),-(y))