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,y) -> q(x,y,y)
 q(x,y,b()) -> r(x,y)
 r(x,b()) -> f(x,b())

Proof:
 Open