English
For a family F, equicontinuity of the restricted family to a subset S is equivalent to equicontinuity of the whole restricted to S.
Русский
Для семейства F равномерная эконтинуальность ограниченной семейство к подмножеству S эквивалентна равномерной эконтинуальности всей F на S.
LaTeX
$$$$ \operatorname{Equicontinuous}(S\restriction F) \iff \operatorname{EquicontinuousOn} F S. $$$$
Lean4
theorem equicontinuous_restrict_iff (F : ι → X → α) {S : Set X} :
Equicontinuous (S.restrict ∘ F) ↔ EquicontinuousOn F S := by
simp [Equicontinuous, EquicontinuousOn, equicontinuousAt_restrict_iff]