proposition: Lemma isunital_ringofendabgr_op2 {G : abgr} : isunital (@ringofendabgr_op2 G).
proof: Proof. exact (make_isunital setofendabgr_un1 isunit_setofendabgr_un1). Defined.
imports: UniMath.MoreFoundations.Tactics UniMath.Algebra.RigsAndRings UniMath.Algebra.Groups UniMath.Algebra.Monoids