approximability

In this paper ,it is proved that if X is a URED Banach space and M is a closed and proximinal subspace of X,then the quotient space X/M is also URED.

证明了若X是URED的Banach空间且M是X的任意可逼近闭子空间 ,则商空间X/M也是URED的Banach空间 。

In this paper,It Is shownthat three types Banachspace there are proximinal sets which lacks property(β).

说明了三种类型的Ｂａｎａｃｈ空间都存在不具有（β）性质的可逼近集，指出在等价范数的意义下，每个具基的Ｂａｎａｃｈ空间都存在不具有（β）性质的可逼近集。