∀ {ι : Type u_1} {X : Type u_2} [inst : EMetricSpace X] {K U : ι → Set X},
  (∀ (i : ι), IsClosed (K i)) →
    (∀ (i : ι), IsOpen (U i)) →
      (∀ (i : ι), K i ⊆ U i) →
        LocallyFinite K → ∃ δ, (∀ (x : X), 0 < δ x) ∧ ∀ (i : ι), ∀ x ∈ K i, Metric.closedEBall x (δ x) ⊆ U i