English
Defining ordSeparatingSet(s,t) as the intersection of the union over s of ordConnectedComponent(tᶜ x) and the union over t of ordConnectedComponent(sᶜ x). It captures points lying between s and t endpoints in different components.
Русский
Определение ordSeparatingSet(s,t) как пересечение объединений ordConnectedComponent(tᶜ x) и ordConnectedComponent(sᶜ x) по соответствующим x из s и t.
LaTeX
$$ordSeparatingSet(s,t) = (⋃ x ∈ s, ordConnectedComponent(t^c, x)) ∩ (⋃ x ∈ t, ordConnectedComponent(s^c, x))$$
Lean4
theorem ordSeparatingSet_comm (s t : Set α) : ordSeparatingSet s t = ordSeparatingSet t s :=
inter_comm _ _