TRS:
 {             zeros() -> cons(0(), n__zeros()),
     tail(cons(X, XS)) -> activate(XS),
               zeros() -> n__zeros(),
  activate(n__zeros()) -> zeros(),
           activate(X) -> X}
 MPO:
  Prec:
   activate > zeros, 
   zeros > n__zeros, 
   zeros > 0, 
   zeros > cons, 
   tail > activate
   empty
  Strict:
   {}
   Weak:
    {}
  Qed