proposition: Lemma Uplus_esp_simpl : forall x y, (x - (x & y))+y == x+y.
proof: Proof. intros; apply (Ule_total ([1-]x) y); auto; intros. rewrite Uminus_esp_simpl_left; auto. rewrite (@Uplus_one x y); auto. rewrite (@Uesp_zero x y); auto. Qed.
imports: ALEA(Utheory)