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

Proof:
 Nonconfluence Processor:
  terms: f(g(f2())) *<- f(f(f(f2()))) ->* g(f(f2()))
  Qed
  
  first automaton:
   final states: {1}
   transitions:
    f(3) -> 1*
    g(2) -> 3*
    f2() -> 2*
  
  second automaton:
   final states: {4}
   transitions:
    f(5) -> 6*
    g(6) -> 4*
    f2() -> 5*