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

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