S-urysohn闭空间的一个特征定理

A CHARACTERISTIC THEOREM OF S-URYSOHN CLOSED SPACE

建立了S-urysohn闭空间关于su-闭集的特征定理并由此得到正则的S-urysohn闭空间是紧空间。同时也证明,极不连通的T_2空间X为S-urysohn闭空间的充要条件是X上的任何一个网都有su-收敛子网。

In this paper a characteristic theorem of S-urysohn closed space is given.It is proved that the regularly closed S-urysohn spaces are compact spaces,that an extremely disconnected Hausdorff space is a S-urysohn closed space,if and only if every net in it has a subnet for su-converge-nce.