English
Let s be nonempty; for a family f_i, if all i ∈ s have ContinuousAt at x, then s.inf' hne f is continuous at x.
Русский
Пусть s непусто; если для всех i ∈ s f_i имеют ContinuousAt в x, то s.inf' hne f непрерывно в x.
LaTeX
$$$
(\text{hne} : s.Nonempty) \Rightarrow (\forall i \in s,\ \text{ContinuousAt}(f_i, x)) \Rightarrow \text{ContinuousAt}\bigl(s.inf' \text{hne} f, x\bigr).$
$$
Lean4
theorem finset_inf' (hne : s.Nonempty) (hs : ∀ i ∈ s, ContinuousAt (f i) x) : ContinuousAt (s.inf' hne f) x := by
simpa only [← Finset.inf'_apply] using finset_inf'_apply hne hs