∀ {C : Type u} [inst : CategoryTheory.Category.{v, u} C] {ι : Type t} {S : C} {X : ι → C} {f : (i : ι) → X i ⟶ S}
  {ι' : Type t'} {X' : ι' → C} {f' : (j : ι') → X' j ⟶ S} {i : ι} {Z : C} (q : Z ⟶ X i) ⦃j : ι'⦄ (a : Z ⟶ X' j),
  autoParam (CategoryTheory.CategoryStruct.comp a (f' j) = CategoryTheory.CategoryStruct.comp q (f i))
      CategoryTheory.Pseudofunctor.DescentData.full_pullFunctor.mem_sieve._auto_1✝ →
    (CategoryTheory.Pseudofunctor.DescentData.full_pullFunctor.sieve✝ f f' i).arrows (CategoryTheory.Over.homMk q ⋯)