∀ {C : Type u} [inst : CategoryTheory.Category.{v, u} C] {A F : CategoryTheory.Functor Cᵒᵖ (Type v)} (η : F ⟶ A)
  (X : Cᵒᵖ)
  (p :
    CategoryTheory.OverPresheafAux.YonedaCollection (CategoryTheory.OverPresheafAux.restrictedYonedaObj η)
      (Opposite.unop X)),
  η.app X (CategoryTheory.OverPresheafAux.unitForward η (Opposite.unop X) p) = p.yonedaEquivFst