Example 2

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

Topologie algébrique, chapter I, § 5. Revêtements principaux

Every covering of degree 2 possesses a unique structure of principal covering of group $\mathbf{Z}/2\mathbf{Z}$ .

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.