YES 1 decompositions #1 ----------- 1: +(0(),x1) -> x1 2: +(x1,+(x2,x3)) -> +(+(x1,x2),x3) 3: +(+(x1,x2),x3) -> +(x1,+(x2,x3)) @Jouannaud and Kirchner's criterion --- R 1: +(0(),x1) -> x1 2: +(x1,+(x2,x3)) -> +(+(x1,x2),x3) 3: +(+(x1,x2),x3) -> +(x1,+(x2,x3)) --- S 1: +(0(),x1) -> x1 2: +(x1,+(x2,x3)) -> +(+(x1,x2),x3) 3: +(+(x1,x2),x3) -> +(x1,+(x2,x3))