English
A map from a compact space to a T2 space is a homeomorphism iff it is continuous and bijective.
Русский
Отображение между компактным пространством и пространством Т2 является гомеоморфизмом тогда и только тогда, когда оно непрерывно и биективно.
LaTeX
$$$\IsHomeomorph f \iff \mathrm{Continuous}(f) \wedge \mathrm{Bijective}(f)$$$
Lean4
/-- A map from a compact space to a T2 space is a homeomorphism iff it is continuous and
bijective. -/
theorem isHomeomorph_iff_continuous_bijective [CompactSpace X] [T2Space Y] :
IsHomeomorph f ↔ Continuous f ∧ Bijective f :=
by
rw [isHomeomorph_iff_continuous_isClosedMap_bijective]
refine and_congr_right fun hf ↦ ?_
rw [eq_true hf.isClosedMap, true_and]