a b : F a b $<~> F b a := Build_CatEquiv (braid a b).
Require Import Basics.Overture Basics.Tactics Types.Forall. Require Import WildCat.Core WildCat.Bifunctor WildCat.Prod WildCat.Equiv. Require Import WildCat.NatTrans WildCat.Opposite.