Problem:
 f(h(f(b()),a())) -> b()
 f(c()) -> b()
 b() -> f(b())

Proof:
 Uncurry Processor:
  f5(f(),f5(f5(h(),f5(f(),b())),a())) -> b()
  f5(f(),c()) -> b()
  b() -> f5(f(),b())
  Ground Confluence Processor:
   non-confluent by decision procedure.