Bourbaki

Corollary

Tag 0464, permanent. Cite it as [Bourbaki, Tag 0464].

Commutative Algebra, chapter II, § 2. Rings and modules of fractions

Under the hypotheses of Proposition 9, let M be an A-module. We write fβα=iMSβ,Sαf_{\beta \alpha} = i^{S_\beta, S_\alpha}_{M} for α≤β,fα=iMS,Sα\alpha \leq \beta, f_\alpha = i^{S, S_\alpha}_{M} for all α∈I\alpha \in I and let fα′f'_\alpha be the canonical mapping from Sα−1MS_\alpha^{-1}M to lim⁡→Sα−1M\lim \rightarrow S_\alpha^{-1}M; then there exists an S−1AS^{-1}A-isomorphism gg of S−1MS^{-1}M onto lim⁡→Sα−1M\lim \rightarrow S_\alpha^{-1}M such that g∘fα=fα′g \circ f_\alpha = f'_\alpha for all a∈Ia \in I.

The corollary follows immediately from the definitions Sα−1M=M⊗ASα−1AS_\alpha^{-1}M = M \otimes_A S_\alpha^{-1}A and S−1M=M⊗AS−1AS^{-1}M = M \otimes_A S^{-1}A and the fact that taking direct limits commutes with tensor products (Algebra, Chapter 11, § 6, no. 3, Proposition 7).

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.