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

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