Problem:
 f(g(x),x,y) -> f(y,y,g(y))
 g(g(x)) -> g(x)

Proof:
 Unfolding Processor:
  loop length: 3
  terms:
   f(g(x),x,g(g(x43)))
   f(g(g(x43)),g(g(x43)),g(g(g(x43))))
   f(g(g(x43)),g(g(x43)),g(g(x43)))
  context: []
  substitution:
   x -> g(x43)
   x43 -> x43
  Qed