【摘要】 解决了近渡点的特征性质，它包括用线性泛函形式（著名的Ｋｏｌｍｏｇｏｒｏｖ型特征性）以及用方向导数表示其特征，从而推广了Ｓｉｎｇｅｒ的最佳逼近点特征理论．更多还原

【Abstract】 The characterization of nearest - cross points of G to F is obtained, where F, C are non -intersecting convex sets. It involves two kinds of characteristics, i. e., representing by linear functional(Kolmogorov - type criteria) and by directional derivatives of . They are established by the theorems of strong separation with distance property due to the present author, and which generalize the characterization property of best approximation of C to one Point given by Singar.更多还原