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

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