∀ {C : Type u} [inst : CategoryTheory.Category.{v, u} C] (J : CategoryTheory.GrothendieckTopology C) {A : Type u'}
  [inst_1 : CategoryTheory.Category.{v', u'} A] [J.IsGeneratedByOneHypercovers] (P : CategoryTheory.Functor Cᵒᵖ A),
  CategoryTheory.Presheaf.IsSheaf J P ↔
    ∀ ⦃X : C⦄ (E : J.OneHypercover X), Nonempty (CategoryTheory.Limits.IsLimit (E.multifork P))