Definition iso_commrig_opposite (X : commrig) : rigiso X (opposite_commrig X). Proof. refine ((idfun X,, idisweq X),, _). repeat split. unfold isbinopfun. exact (λ x y, rigcomm2 X x y). Defined.
Require Import UniMath.Algebra.Groups. Require Import UniMath.MoreFoundations.Sets. Require Import UniMath.MoreFoundations.Orders.