摘要
得到了实赋范线性空间Ｘ的闭有限余维子空间是ｋ半Ｃｈｅｂｙｓｈｅｖ的特征，因而得到了Ｘ的弱闭有限余维子空间是ｋ－Ｃｈｅｂｙｓｈｅｖ的特征，并把后一个结果用到Ｃ０和Ｌ１，得到到更简明的结果。
We obtain the characterization for the closed subspace of finite codimension of any real normed linear space to be k—semi—Chebyshev,therefore,the characterization for the weekly closed subspace of finite codimension to be k—Chebychev.We also obtain more simple results by using the latter result in C_0 and L_1.
关键词
实赋范线性空间
最佳逼近
延拓
空间理论
Real mormed linear space
Subspace ofcodimension
Conven set
Dimension
Best approxiations
Extension
