YES

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

@Jouannaud and Kirchner's criterion
--- R
   1: +(x,y) -> +(y,x)
   2: +(0(),y) -> y
   3: +(x,0()) -> x
   4: +(s(x),y) -> s(+(x,y))
   5: +(x,+(y,z)) -> +(+(x,y),z)

--- S
   1: +(x,y) -> +(y,x)
   2: +(0(),y) -> y
   3: +(x,0()) -> x
   4: +(s(x),y) -> s(+(x,y))
   5: +(x,+(y,z)) -> +(+(x,y),z)