fact: Definition yon_cancel_0gpd {A : Type} `{Is1Cat A} (a b : A) : (yon_0gpd a $=> yon_0gpd b) -> (a $-> b) := opyon_cancel_0gpd (A:=A^op) a b.
imports: Basics.Overture Basics.Tactics WildCat.Core WildCat.Equiv WildCat.Universe WildCat.Opposite WildCat.FunctorCat WildCat.NatTrans WildCat.Prod WildCat.ZeroGroupoid