YES

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

Proof:
 Uncurry Processor:
  a() -> b()
  f4(f(),a()) -> f4(g(),a())
  f4(f(),b()) -> f4(g(),b())
  Ground Confluence Processor:
   confluent by decision procedure.