Bourbaki

Proposition 4

Tag 0C78, permanent. Cite it as [Bourbaki, Tag 0C78].

General Topology, chapter IX, § 5. Baire spaces

If every point of a topological space XX has a neighbourhood which is a Baire space, then XX is a Baire space.

Let AA be a non-empty open set in XX, let x∈Ax \in A and let VV be an open neighbourhood of xx which is a Baire space. If AA were meagre in XX, then V∩AV \cap A would be meagre in VV and open in VV, which is contrary to hypothesis.

Bourbaki puts the proof directly after the statement, so what is above is the statement and its proof together.

Cited by

Cites

Nothing.

Transcribed from the printed volume. Not translated.