{A B : Type} `{IsGraph A} `{Is1Cat B} (F G : A -> B) {ff : Is0Functor F} {fg : Is0Functor G} : _ <~> NatTrans F G := ltac:(issig).
Require Import Basics.Overture Basics.Tactics. Require Import WildCat.Core. Require Import WildCat.Equiv. Require Import WildCat.Square. Require Import WildCat.Opposite.