Problem:
 a() -> a()
 g(a()) -> b()
 g(a()) -> g(g(a()))
 g(b()) -> a()

Proof:
 Uncurry Processor:
  a() -> a()
  f3(g(),a()) -> b()
  f3(g(),a()) -> f3(g(),f3(g(),a()))
  f3(g(),b()) -> a()
  Ground Confluence Processor:
   UN by decision procedure.