Bourbaki

Example 1

Tag 01W9, permanent. Cite it as [Bourbaki, Tag 01W9].

Topologie algébrique, chapter III, § 1. Homotopies, homéotopies

Let X and Y be topological spaces and let f:X→Yf: X\rightarrow Y be a continuous mapping. The cylinder Cyl(ff) is none other than the space obtained by attaching the space Y to the space X×IX\times \mathbf{I} along the mapping f∘f\circ pr1_1 of X×{1}X\times \{1\} into Y.

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

Nothing.

Cites

Nothing.

Machine translation of the English, by gpt-5.4, gpt-5-6-mini, gpt-5-mini, against glossary version 34. Not checked by a person. That model is a cut down version of the one the rest of this language was written by.