摘要
本文证明了μ＊可测集族Ａ＊的一个重要性质，即对于由Ａ上的测度引出的外测度μ＊。
In this paper we prove an important property of the family A * of μ * measurable sets. That is, for the outer measure μ * derived from measure μ on A, A * is the largest σ algebra in the σ algebras containing A and making μ * as a measure on itself.
关键词
测度
外测度
μ可测集
Σ代数
measure outer measure μ * measurable set family of μ * measurable sets
