YES

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

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

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