proposition: Lemma isrunit_setofendabgr_un0 {G : abgr} : isrunit (@ringofendabgr_op1 G) setofendabgr_un0.
proof: Proof. intros f. use total2_paths_f. - apply funextfun. intro x. apply (runax G (pr1setofendabgr f x)). - apply isapropismonoidfun. Defined.
imports: UniMath.MoreFoundations.Tactics UniMath.Algebra.RigsAndRings UniMath.Algebra.Groups UniMath.Algebra.Monoids