Lemma islunit_setofendabgr_un1 {G : abgr} : islunit (@ringofendabgr_op2 G) setofendabgr_un1. Proof. intro f. use total2_paths_f. - apply funextfun. intro x. reflexivity. - apply isapropismonoidfun. Defined.
Require Import UniMath.MoreFoundations.Tactics. Require Import UniMath.Algebra.RigsAndRings. Require Import UniMath.Algebra.Groups. Require Import UniMath.Algebra.Monoids.