NO

1 decompositions
 #0 -----------
   1: a() -> f(b())
   2: h(b(),f(c())) -> c()
   3: b() -> f(b())
   4: b() -> f(c())
   5: h(c(),c()) -> c()

unjoinable peak
    h(f(b()),f(c()))
*<- h(b(),f(c())) ->*
    c()