English
Continuous equivalences from a compact space to a T2 space are homeomorphisms.
Русский
Непрерывные эквивалентности между компактным пространством и пространством Т2 являются гомеоморфизмами.
LaTeX
$$$\exists h : X \simeq_{\mathrm{Top}} Y, h = f$$$
Lean4
/-- Continuous equivalences from a compact space to a T2 space are homeomorphisms.
This is not true when T2 is weakened to T1
(see `Continuous.homeoOfEquivCompactToT2.t1_counterexample`). -/
@[simps toEquiv]
def homeoOfEquivCompactToT2 [CompactSpace X] [T2Space Y] {f : X ≃ Y} (hf : Continuous f) : X ≃ₜ Y :=
{ f with
continuous_toFun := hf
continuous_invFun := hf.continuous_symm_of_equiv_compact_to_t2 }