{A} `{HasEquivs A} {a b : A} (f : a $<~> b) : cate_fun (id_cate b $oE f) $== cate_fun f. Proof. refine (compose_cate_fun _ f $@ _ $@ cat_idl f). refine (cate_buildequiv_fun _ $@R _). Defined.
Require Import Basics.Utf8 Basics.Overture Basics.Tactics Basics.Equivalences. Require Import WildCat.Core. Require Import WildCat.Opposite.