proposition: Theorem eqalters_I : EqSt alter1 alter2.
proof: Proof. apply (buildeq Invariant). intros. case H. intros. case H0. intros. rewrite H1; rewrite H2. simpl in |- *. split. trivial. unfold Invariant in |- *. exists (negb x0). unfold gen1 in |- *. unfold gen2 in |- *. split. trivial. trivial. unfold Invariant in |- *. exists false. split. trivial. trivial. Qed.
imports: Bool