fact: Definition opyon_cancel {A : Type} `{Is01Cat A} (a b : A) : (opyon a $=> opyon b) -> (b $-> a) := un_opyoneda a (opyon b).
imports: Basics.Overture Basics.Tactics WildCat.Core WildCat.Equiv WildCat.Universe WildCat.Opposite WildCat.FunctorCat WildCat.NatTrans WildCat.Prod WildCat.ZeroGroupoid