English
If h is HasProdLocallyUniformlyOn f g s, then TendstoLocallyUniformlyOn with Finset.range range converges on s.
Русский
Если h = HasProdLocallyUniformlyOn f g s, тогда TendstoLocallyUniformlyOn с диапазона Finset.range сходится на s.
LaTeX
$$$ (h : HasProdLocallyUniformlyOn f g s) \Rightarrow TendstoLocallyUniformlyOn (\lambda N b. (Finset.range N).prod (λ i, f i b)) g atTop s $$$
Lean4
@[to_additive]
theorem tendstoLocallyUniformlyOn_finsetRange {f : ℕ → β → α} (h : HasProdLocallyUniformlyOn f g s) :
TendstoLocallyUniformlyOn (fun N b ↦ ∏ i ∈ Finset.range N, f i b) g atTop s :=
by
rw [hasProdLocallyUniformlyOn_iff_tendstoLocallyUniformlyOn] at h
intro v hv r hr
obtain ⟨t, ht, htr⟩ := h v hv r hr
exact ⟨t, ht, Filter.tendsto_finset_range.eventually htr⟩