English
Filtration equality of sets along a filter is equivalent to pointwise membership agreement along the filter.
Русский
Эквивалентность по фильтру множеств эквивалентна согласованности по членству на каждом элементе фильтра.
LaTeX
$$$s =^{{l}} t \\iff \\forall^{{\\text{freq}}}_{x\\in l} (x\\in s \\iff x\\in t)$$$
Lean4
theorem eventuallyEq_set {s t : Set α} {l : Filter α} : s =ᶠ[l] t ↔ ∀ᶠ x in l, x ∈ s ↔ x ∈ t :=
eventually_congr <| Eventually.of_forall fun _ ↦ eq_iff_iff