∀ (S : CategoryTheory.Functor Type uᵒᵖ (Type u))
  (hs : CategoryTheory.Presheaf.IsSheaf CategoryTheory.typesGrothendieckTopology S) (X : Type uᵒᵖ)
  (a : (CategoryTheory.yoneda.obj (S.obj (Opposite.op PUnit.{u + 1}))).obj X),
  (CategoryTheory.equivYoneda S hs).inv.app X a = (CategoryTheory.evalEquiv S hs (Opposite.unop X)).symm a