∀ {X Y : TopCat} {f : X ⟶ Y} (hf : IsOpenMap ⇑(CategoryTheory.ConcreteCategory.hom f)) (x : TopologicalSpace.Opens ↑Y)
  (x_1 : ↑Y) (motive : x_1 ∈ ((TopologicalSpace.Opens.map f).comp hf.functor).obj x → Prop)
  (x_2 : x_1 ∈ ((TopologicalSpace.Opens.map f).comp hf.functor).obj x),
  (∀ (w : ↑X) (hfxV : w ∈ ↑((TopologicalSpace.Opens.map f).obj x))
      (hxy : (CategoryTheory.ConcreteCategory.hom f) w = x_1), motive ⋯) →
    motive x_2