English
For any X and filters F, G, AccPt x (F ⊔ G) holds iff AccPt x F or AccPt x G holds.
Русский
Для любых X, фильтров F, G: AccPt x (F ⊔ G) эквивалентно AccPt x F или AccPt x G.
LaTeX
$$$\\mathrm{AccPt}(x, F \\sqcup G) \\iff \\mathrm{AccPt}(x,F) \\lor \\mathrm{AccPt}(x,G)$$$
Lean4
theorem accPt_sup {x : X} {F G : Filter X} : AccPt x (F ⊔ G) ↔ AccPt x F ∨ AccPt x G := by
simp only [AccPt, inf_sup_left, sup_neBot]