proposition: Lemma is_folds_precat_implies_is_univalent : is_univalent_folds_pre_2_cat C.
proof: Proof. intros a b f g. apply isweqimplimpl. - apply folds_2_iso_implies_identity. - apply (pr1 H). - apply isaprop_folds_2_iso. Qed.
imports: UniMath.Folds.UnicodeNotations UniMath.Foundations.PartD UniMath.Foundations.Propositions UniMath.Foundations.Sets