Lemma 10.52.6. Let R be a ring with maximal ideal \mathfrak m. Suppose that M is an R-module with \mathfrak m M = 0. Then the length of M as an R-module agrees with the dimension of M as a R/\mathfrak m vector space. The length is finite if and only if M is a finite R-module.
Proof. The first part is a special case of Lemma 10.52.5. Thus the length is finite if and only if M has a finite basis as a R/\mathfrak m-vector space if and only if M has a finite set of generators as an R-module. \square
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