YES 1 decompositions #0 ----------- 1: -(0(),0()) -> 0() 2: -(s(x),0()) -> s(x) 3: -(x,s(y)) -> -(d(x),y) 4: d(s(x)) -> x 5: -(s(x),s(y)) -> -(x,y) 6: -(d(x),y) -> -(x,s(y)) @Strongly Commuting --- R 1: -(0(),0()) -> 0() 2: -(s(x),0()) -> s(x) 3: -(x,s(y)) -> -(d(x),y) 4: d(s(x)) -> x 5: -(s(x),s(y)) -> -(x,y) 6: -(d(x),y) -> -(x,s(y)) --- S 1: -(0(),0()) -> 0() 2: -(s(x),0()) -> s(x) 3: -(x,s(y)) -> -(d(x),y) 4: d(s(x)) -> x 5: -(s(x),s(y)) -> -(x,y) 6: -(d(x),y) -> -(x,s(y))