NO

peak

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

is not joinable