∀ {C : Type u₁} [inst : CategoryTheory.Category.{v₁, u₁} C] {A : Type u₂} [inst_1 : CategoryTheory.Category.{v₂, u₂} A]
  (J : CategoryTheory.GrothendieckTopology C) (P : CategoryTheory.Functor Cᵒᵖ A),
  CategoryTheory.Presheaf.IsSheaf J P =
    ∀ (E : A), CategoryTheory.Presieve.IsSheaf J (P.comp (CategoryTheory.coyoneda.obj (Opposite.op E)))