Lemma isapropisrigfun {X Y : rig} (f : X → Y) : isaprop (isrigfun f). Proof. use isapropdirprod. - use isapropismonoidfun. - use isapropismonoidfun. Qed.
Require Import UniMath.Algebra.Groups. Require Import UniMath.MoreFoundations.Sets. Require Import UniMath.MoreFoundations.Orders.