∀ {C : Type u} [inst : CategoryTheory.Category.{v, u} C] (J : CategoryTheory.GrothendieckTopology C) (A : Type u')
  [inst_1 : CategoryTheory.Category.{v', u'} A] {X Y : C} (f : X ⟶ Y),
  CategoryTheory.CategoryStruct.comp (J.overMapPullbackComp A (CategoryTheory.CategoryStruct.id X) f).inv
      (CategoryTheory.CategoryStruct.comp ((J.overMapPullback A f).whiskerLeft (J.overMapPullbackId A X).hom)
        (J.overMapPullback A f).rightUnitor.hom) =
    (J.overMapPullbackCongr A ⋯).hom