fact: Definition Yoneda_spec2 `{F : Functor} `{G : Functor} `(H : F [≅] G) {X} : Hom X ◌ F [≅] Hom X ◌ G.
imports: Ssreflect.choice Basics Endo FCompose Coq.Classes.Morphisms Coq.Setoids.Setoid Coq.Relations.Relation_Definitions