(** we now generalize the theorem to the nth-root *)
Fixpoint power (x n:nat) {struct n} : nat :=
  match n with
    O => 1
    | (S n) => (x*(power x n))
  end.

Lemma power_divides_power : forall (x n m:nat),(x>1)->(divides (power x n) (power x m))->(m<=n).