Bourbaki

Proposition 1

Tag 0B3Z, permanent. Cite it as [Bourbaki, Tag 0B3Z].

General Topology, chapter I, § 6. Filters

A necessary and sufficient condition that there should exist a filter on XX containing a set G\mathfrak{G} of subsets of XX is that no finite subset of G\mathfrak{G} has an empty intersection.

The filter G′′\mathfrak{G}'' defined above is said to be generated by G\mathfrak{G}, and G\mathfrak{G} is said to be a subbase of G′′\mathfrak{G}''.

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.