proposition: Lemma andb_true : forall a b : Bool, andb a b = true -> a = true /\ b = true.
proof: Proof. intros [|] [|];simpl;auto. Qed.
imports: HoTT.Classes.interfaces.abstract_algebra HoTT.Classes.theory.additional_operations HoTT.Classes.tactics.ring_quote HoTT.Classes.theory.rings