NO

1 decompositions
 #1 -----------
   1: +(0(),0()) -> 0()
   2: +(s(x1),x2) -> s(+(x1,x2))
   3: +(x3,s(x4)) -> s(+(x4,x3))
   4: s(s(x5)) -> x5

unjoinable peak
    +(x14,x1)
*<- +(s(x1),s(x14)) ->*
    +(x1,x14)