∀ {J : Type u_1} {C : Type u_2} [inst : CategoryTheory.Category.{v_1, u_1} J]
  [inst_1 : CategoryTheory.Category.{v_2, u_2} C] (F : CategoryTheory.Functor J Cᵒᵖ) (X : C)
  (τ : (CategoryTheory.Functor.const J).obj (Opposite.op X) ⟶ F) (j : J),
  ↑((CategoryTheory.Limits.compYonedaSectionsEquiv F X).symm τ) j = (τ.app j).unop