Bourbaki

Corollary 3

Tag 04G3, permanent. Cite it as [Bourbaki, Tag 04G3].

Commutative Algebra, chapter III, § 3. m-adic topologies on Noetherian rings

*Let A be a commutative Noetherian ring, m an ideal of A and x an element of AA which is not a divisor of OO. There exists an integer k>0k > 0 such that, for all n≥kn \geq k, the relation xy∈mnxy \in m^n implies y∈mn−ky \in m^{n-k}.

Corollary 1 applied to E=A,F=AxE = A, F = A x shows that there exists kk such that, for all n≥kn \geq k, mn∩Ax=mn−k(mk∩Ax)m^n \cap Ax = m^{n-k}(m^k \cap Ax). Then, if xy∈mnxy \in m^n,

xy∈mn∩Ax⊂mn−kx xy \in m^n \cap Ax \subset m^{n-k}x

and, as xx is not a divisor of 00, we deduce that y∈mn−ky \in m^{n-k}.

In the notation of transporters (Chapter I, § 2, no. 10), the conclusion of Corollary 3 reads

(2)

mn:Ax⊂mn−k. m^n : Ax \subset m^{n-k}.

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

Cited by

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Cites

Transcribed from the printed volume. Not translated.