MAYBE
MAYBE
TRS:
 {
        mark(cons(X1, X2)) -> cons(mark(X1), X2),
             mark(from(X)) -> a__from(mark(X)),
                mark(s(X)) -> s(mark(X)),
                 mark(0()) -> 0(),
         mark(sel(X1, X2)) -> a__sel(mark(X1), mark(X2)),
                a__from(X) -> cons(mark(X), from(s(X))),
                a__from(X) -> from(X),
            a__sel(X1, X2) -> sel(X1, X2),
  a__sel(s(X), cons(Y, Z)) -> a__sel(mark(X), mark(Z)),
   a__sel(0(), cons(X, Y)) -> mark(X)
 }
 DUP: We consider a duplicating system.
  Trs:
   {
          mark(cons(X1, X2)) -> cons(mark(X1), X2),
               mark(from(X)) -> a__from(mark(X)),
                  mark(s(X)) -> s(mark(X)),
                   mark(0()) -> 0(),
           mark(sel(X1, X2)) -> a__sel(mark(X1), mark(X2)),
                  a__from(X) -> cons(mark(X), from(s(X))),
                  a__from(X) -> from(X),
              a__sel(X1, X2) -> sel(X1, X2),
    a__sel(s(X), cons(Y, Z)) -> a__sel(mark(X), mark(Z)),
     a__sel(0(), cons(X, Y)) -> mark(X)
   }
  Fail