Bourbaki

Corollary 3

Tag 01P2, permanent. Cite it as [Bourbaki, Tag 01P2].

Topologie algébrique, chapter I, § 4. Revêtements

Let B be a topological space. Let E and E′E' be locally trivial fibre B-spaces ( resp. coverings). Then E×BE′E\times_BE' is a locally trivial fibre B-space ( resp. a covering of B). It is trivializable if E and E′E' are.

This follows from corollary 1, applied to the case where A, B and B′B' are equal.

Bourbaki sets the proof directly after the statement, and the corpus does not separate them, so what is above is the statement and its proof together.

Cited by

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Cites

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Machine translation of the English, by gpt-5.4, against glossary version 34. Not checked by a person.