Lemma rig_equiv_z_iso (X Y : ob rig_category) : rigiso (X : rig) (Y : rig) -> z_iso X Y. Proof. intros f. exists (rigfunconstr (pr2 f)). exact (rig_equiv_is_z_iso X Y f). Defined.
Require Import UniMath.Foundations.PartD. Require Import UniMath.Foundations.Propositions. Require Import UniMath.Foundations.Sets. Require Import UniMath.Foundations.UnivalenceAxiom. Require Import UniMath.Algebra.BinaryOperations. Require Import UniMath.Algebra.Monoids. Require Import UniMath.Algebra.RigsAndRings. Require Import UniMath.CategoryTheory.Core.Categories. Require Import UniMath.CategoryTheory.Core.Isos. Require Import UniMath.CategoryTheory.Core.Univalence.