English
A nonempty compact can be viewed as a closed set in a Hausdorff space: toCloseds(s) = ⟨s, s.isCompact.isClosed⟩.
Русский
Непустый компакт можно рассматривать как замкнутое множество в Хаусдорфовом пространстве: toCloseds(s) = ⟨s, s.isCompact.isClosed⟩.
LaTeX
$$$[T2Space \\alpha] (s : \\mathrm{NonemptyCompacts}(\\alpha)) \\Rightarrow \\text{toCloseds }(s) = \\langle s, s.isCompact.isClosed \\rangle$$$
Lean4
/-- Reinterpret a nonempty compact as a closed set. -/
def toCloseds [T2Space α] (s : NonemptyCompacts α) : Closeds α :=
⟨s, s.isCompact.isClosed⟩