Bourbaki

Corollary

Tag 0BF1, permanent. Cite it as [Bourbaki, Tag 0BF1].

General Topology, chapter II, § 3. Complete spaces

Let (Xα,fαβ)(X_\alpha, f_{\alpha\beta}) be an inverse system of uniform spaces. If the XαX_\alpha are Hausdorff and complete, then so is X=lim←⁡XαX = \varprojlim X_\alpha.

For XX is Hausdorff and can be identified with a closed subspace of ∏i∈IXα\prod_{i \in I} X_\alpha (Chapter I, § 8, no. 2, Corollary 2 to Proposition 7); the corollary therefore follows from Proposition 10 and Proposition 8 (no. 4).

An inverse limit of complete Hausdorff uniform spaces XαX_\alpha can be empty, even if all the XαX_\alpha are non-empty and all the fαβf_{\alpha\beta} are surjective, as is shown by the case of discrete spaces (Set Theory, Chapter III, § 1, Exercise 32). However, we have the following theorem:

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

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