MAYBE
MAYBE
TRS:
 {
                     from(X) -> cons(X, n__from(s(X))),
                     from(X) -> n__from(X),
               first(X1, X2) -> n__first(X1, X2),
     first(s(X), cons(Y, Z)) -> cons(Y, n__first(X, activate(Z))),
               first(0(), Z) -> nil(),
                 activate(X) -> X,
        activate(n__from(X)) -> from(X),
  activate(n__first(X1, X2)) -> first(X1, X2),
       sel(s(X), cons(Y, Z)) -> sel(X, activate(Z)),
        sel(0(), cons(X, Z)) -> X
 }
 DUP: We consider a duplicating system.
  Trs:
   {
                       from(X) -> cons(X, n__from(s(X))),
                       from(X) -> n__from(X),
                 first(X1, X2) -> n__first(X1, X2),
       first(s(X), cons(Y, Z)) -> cons(Y, n__first(X, activate(Z))),
                 first(0(), Z) -> nil(),
                   activate(X) -> X,
          activate(n__from(X)) -> from(X),
    activate(n__first(X1, X2)) -> first(X1, X2),
         sel(s(X), cons(Y, Z)) -> sel(X, activate(Z)),
          sel(0(), cons(X, Z)) -> X
   }
  Fail