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