MAYBE
MAYBE
TRS:
 {
            a__zeros() -> cons(0(), zeros()),
            a__zeros() -> zeros(),
    mark(cons(X1, X2)) -> cons(mark(X1), X2),
             mark(0()) -> 0(),
         mark(zeros()) -> a__zeros(),
         mark(tail(X)) -> a__tail(mark(X)),
            a__tail(X) -> tail(X),
  a__tail(cons(X, XS)) -> mark(XS)
 }
 DUP: We consider a non-duplicating system.
  Trs:
   {
              a__zeros() -> cons(0(), zeros()),
              a__zeros() -> zeros(),
      mark(cons(X1, X2)) -> cons(mark(X1), X2),
               mark(0()) -> 0(),
           mark(zeros()) -> a__zeros(),
           mark(tail(X)) -> a__tail(mark(X)),
              a__tail(X) -> tail(X),
    a__tail(cons(X, XS)) -> mark(XS)
   }
  Fail