English
Lebesgue number lemma in the nhds' topology setting: given compact s and a family of sets c defined by neighborhoods, there exists δ > 0 such that ...
Русский
Лебегов номер в окружении nhds' : при компактности s существует δ > 0 такое, что ...
LaTeX
$$lebesgue_number_lemma_nhds' hs hc$$
Lean4
theorem lebesgue_number_lemma_of_emetric_nhds' {c : (x : α) → x ∈ s → Set α} (hs : IsCompact s)
(hc : ∀ x hx, c x hx ∈ 𝓝 x) : ∃ δ > 0, ∀ x ∈ s, ∃ y : s, ball x δ ⊆ c y y.2 := by
simpa only [ball, UniformSpace.ball, preimage_setOf_eq, edist_comm] using
uniformity_basis_edist.lebesgue_number_lemma_nhds' hs hc