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

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