NO

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

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