摘要
本文证明了：设Ｒ为ｃｈａｒＲ≠０，Ｇ为有限生成的Ａｂｅｌ群，则：Ｐ∈Ｆ＝（ＲＧ）当且仅当ｓ＞０，使得Ｐｓ∈Ｆ＝（ＲＧ）．
In this paper, we obtain the following result: Let R be ring with charR≠0, G be a finitely generated abelian group. Then P is a finitely generated free RG module if and only if there exists some s>0 such that P s is a finitely generated free RG modules.
