English
The centralizer of a union equals the intersection of the centralizers: centralizer(S ∪ T) = centralizer(S) ∩ centralizer(T).
Русский
Централизатор объединения равен пересечению централизаторов: centralizer(S ∪ T) = centralizer(S) ∩ centralizer(T).
LaTeX
$$$ \mathrm{centralizer}(S \cup T) = \mathrm{centralizer}(S) \cap \mathrm{centralizer}(T) $$$
Lean4
@[to_additive addCentralizer_union]
theorem centralizer_union : centralizer (S ∪ T) = centralizer S ∩ centralizer T := by
simp [centralizer, or_imp, forall_and, setOf_and]