NO

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

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