Proposition 1
Tag 0BZK, permanent. Cite it as [Bourbaki, Tag 0BZK].
General Topology, chapter VII, § 3. Infinite sums in the groups $\mathbf{R}^n$
A family of points of is summable if and only if each of the families of real numbers is summable in .
This follows from Chapter III, § 5, no. 4, Proposition 4.
The condition of Proposition 1 may be transformed as follows:
Bourbaki puts the proof directly after the statement, so what is above is the statement and its proof together.