(SIG
   (b   -> o)
   (h   o o -> o)
   (c   -> o)
   (f   o -> o)
   (a   -> o)
)
(RULES
   b -> h(c,f(b))
   a -> c
   h(h(h(f(a),a),a),f(f(f(h(h(f(b),b),b))))) -> a
   c -> h(f(h(c,f(f(c)))),f(b))
)