`{!IsSurjInj G} : SplEssSurj (G o F) <-> SplEssSurj F. Proof. split; [ apply @cancelL_isesssurj | apply @isesssurj_compose ]; exact _. Defined.
Require Import Basics.Overture Basics.Tactics Basics.Iff. Require Import WildCat.Core. Require Import WildCat.NatTrans. Require Import WildCat.Sigma.