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