Bourbaki

Proposition 4

Tag 0C8J, permanent. Cite it as [Bourbaki, Tag 0C8J].

General Topology, chapter IX, § 6. Polish spaces, Souslin spaces, Borel sets

Every Souslin space XX is of countable type.

Let PP be a Polish space and ff a continuous mapping of PP onto XX. Then the image under ff of a countable dense subset of PP is a countable dense subset of XX.

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

Cited by

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Cites

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Transcribed from the printed volume. Not translated.