在这份报纸,有一个局部地可计算的 sn 网络的空格被讨论。它空间与它是的局部地可计算的 sn 网络见被看那有局部地可计算的 k 网络的一个 snf 可计算的空格。作为它的应用程序,几乎打开和关上的 mappings (或 finite-to-one 并且印射关上) 与一个局部地可计算的 sn 网络在空格保存局部地可计算的 sn 网络,和一条完美的 preimage 定理被建立。
In this paper,spaces with a locally countable sn-network are discussed.It is shown that a space with a locally countable sn-network iff it is an snf-countable space with a locally countable k-network.As its application,almost-open and closed mappings(or finite-to-one and closed mapping) preserve locally countable sn-networks,and a perfect preimage theorem on spaces with a locally countable sn-network is established.