End IN_Q_EFFECT.
Section CARD_EFFECT.
(* consequence sur le nombre *)

Lemma post_card_mess :
forall (m : Message) (s1 s2 : Site) (b : Bag_of_message),
card_mess m (Post_message m b s1 s2 s1 s2) = (card_mess m (b s1 s2) + 1)%Z.