Lemma symmetric_whiskers_swap_is_nat_trans {C : category} {M : monoidal C} (B : symmetric M) (x : C) : is_nat_trans _ _ (symmetric_whiskers_swap_nat_trans_data B x). Proof. intros y1 y2 g. exact (! monoidal_braiding_naturality_left B x y1 y2 g). Qed.
Require Import UniMath.Foundations.All. Require Import UniMath.MoreFoundations.All. Require Import UniMath.CategoryTheory.Core.Categories. Require Import UniMath.CategoryTheory.Core.Isos. Require Import UniMath.CategoryTheory.Core.Functors. Require Import UniMath.CategoryTheory.Core.NaturalTransformations. Require Import UniMath.CategoryTheory.Monoidal.WhiskeredBifunctors. Require Import UniMath.CategoryTheory.Monoidal.Categories. Import BifunctorNotations. Import MonoidalNotations.