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