proposition: Lemma grtoltunel (X : gr) {R : hrel X} (is : isbinophrel R) {x : X} (isg : R (grinv X x) (unel X)) : R (unel X) x.
proof: Proof. assert (r := (pr1 is) _ _ x isg). rewrite (grrinvax X x) in r. rewrite (runax X _) in r. apply r. Defined.
imports: UniMath.MoreFoundations.Orders UniMath.MoreFoundations.Tactics UniMath.MoreFoundations.Subtypes UniMath.Algebra.BinaryOperations UniMath.Algebra.Monoids