MAYBE Problem: g(f(b(),x)) -> g(h(h(f(f(h(k(k(x,x),x)),h(k(k(x,x),x))),h(k(k(x,x),x)))))) f(x,b()) -> h(f(f(x,x),x)) k(x,b()) -> q(x) q(x) -> f(x,b()) Proof: Open