Bourbaki

Proposition 9

Tag 04NI, permanent. Cite it as [Bourbaki, Tag 04NI].

Commutative Algebra, chapter V, § 1. Notion of an integral element

Let AA be a ring, (Ri)1≤i≤n(R_i)_{1 \leq i \leq n} a finite family of AA-algebras and Ai′A'_i the integral closure of AA in RiR_i, (1≤i≤n)(1 \leq i \leq n). Then the integral closure of AA in R=∏i=1nRiR = \prod_{i=1}^n R_i, is equal to ∏i=1nAi′\prod_{i=1}^n A'_i.

This is an immediate consequence of no. 1, Proposition 3.

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.