intros H'; absurd (prime 0); auto.
intros n; case n.
intros H'; absurd (prime 1); auto.
intros n0; case n0; auto with arith.
Qed.

(* Specifications: *)
Lemma phi_gt_SO : 1 < pq.
Theorem rsa_correct :
forall w : nat, congruent (p * q) (decrypt (encrypt w)) w.