MAYBE
MAYBE
TRS:
 {
     g(empty(), d) -> d,
  g(cons(x, k), d) -> g(k, cons(x, d)),
     f(a, empty()) -> g(a, empty()),
  f(a, cons(x, k)) -> f(cons(x, a), k)
 }
 DUP: We consider a non-duplicating system.
  Trs:
   {
       g(empty(), d) -> d,
    g(cons(x, k), d) -> g(k, cons(x, d)),
       f(a, empty()) -> g(a, empty()),
    f(a, cons(x, k)) -> f(cons(x, a), k)
   }
  Fail