∀ {C : Type u₁} [inst : CategoryTheory.Category.{v₁, u₁} C] {J : CategoryTheory.GrothendieckTopology C} {A : Type u₂}
  [inst_1 : CategoryTheory.Category.{v₂, u₂} A] (x : CategoryTheory.Sheaf J A),
  (CategoryTheory.CategoryStruct.id x).val = CategoryTheory.CategoryStruct.id x.val