MAYBE
Trs:
 {2nd(cons1(X, cons(Y, Z))) -> Y,
           2nd(cons(X, X1)) -> 2nd(cons1(X, activate(X1))),
                    from(X) -> cons(X, n__from(s(X))),
                    from(X) -> n__from(X),
       activate(n__from(X)) -> from(X),
                activate(X) -> X}
 Comment:
  We consider a duplicating trs.
  FAIL:
   Open