YES

1 decompositions
 #0 -----------
   1: -(+(x,y)) -> +(-(x),-(y))
   2: +(x,y) -> +(y,x)
   3: +(+(x,y),z) -> +(x,+(y,z))

@Jouannaud and Kirchner's criterion
--- R
   1: -(+(x,y)) -> +(-(x),-(y))
   2: +(x,y) -> +(y,x)
   3: +(+(x,y),z) -> +(x,+(y,z))

--- S
   1: -(+(x,y)) -> +(-(x),-(y))
   2: +(x,y) -> +(y,x)
   3: +(+(x,y),z) -> +(x,+(y,z))