Bourbaki

Remark

Tag 0CA7, permanent. Cite it as [Bourbaki, Tag 0CA7].

General Topology, chapter IX, Appendix 0. Infinite products in normed algebras

If (xn)(x_n) is multipliable and its product is not a unit, the condition of Theorem 1 is not necessarily satisfied: for example, if all the xnx_n are equal to the same element xx, where ∥x∥<1\|x\| < 1, the sequence (xn)(x_n) is multipliable and its product is 0, and for each non-empty finite subset HH of N\mathbf{N}, we have ∥pH∥≤∥x∥<1≤∥e∥\|p_H\| \leq \|x\| < 1 \leq \|e\|.

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

Cited by

Nothing.

Cites

Transcribed from the printed volume. Not translated.