Bourbaki

Proposition 1

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

General Topology, chapter II, § 3. Complete spaces

In a uniform space XX, if two sets AA and BB are VV-small and intersect, then their union A∪BA \cup B is V⃗\vec{V}-small.

Let xx and yy be any two points of A∪BA \cup B, and let Z∈A∩BZ \in A \cap B. Then (x,z)∈V(x, z) \in V and (z,y)∈V(z, y) \in V, so that (x,y)∈V‾(x, y) \in \overline{V}.

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

Cited by

Cites

Nothing.

Transcribed from the printed volume. Not translated.