MAYBE
MAYBE
TRS:
 {
        f(a(x), b()) -> f(b(), a(x)),
             a(a(x)) -> f(b(), a(f(a(x), b()))),
  a(a(f(b(), a(x)))) -> f(a(a(a(x))), b())
 }
 DUP: We consider a non-duplicating system.
  Trs:
   {
          f(a(x), b()) -> f(b(), a(x)),
               a(a(x)) -> f(b(), a(f(a(x), b()))),
    a(a(f(b(), a(x)))) -> f(a(a(a(x))), b())
   }
  Fail