proposition: Lemma different_queue1 : forall (E : Set) (q : queue E) (m : E), input E m q <> first_out E q.
proof: Proof. intro. simple induction q. simpl in |- *. intros. discriminate. intros. simpl in |- *. generalize H. case q0. simpl in |- *. intros. discriminate. intros. cut (input E d (input E e q1) <> first_out E (input E e q1)). intro. injection. intros. elim H1; auto. auto. Qed.
imports: List DistributedReferenceCounting.machine2.invariant8