fact: Definition yon_0gpd {A : Type} `{Is1Cat A} (a : A) : A^op -> ZeroGpd := opyon_0gpd (A:=A^op) a.
imports: Basics.Overture Basics.Tactics WildCat.Core WildCat.Equiv WildCat.Universe WildCat.Opposite WildCat.FunctorCat WildCat.NatTrans WildCat.Prod WildCat.ZeroGroupoid