摘要
本文用收敛类诱导出满足第一可数公理的拓扑空间,并得到一个拓扑空间满足第一可数公理的充要条件。
In this paper, the firist countability axiom is described by using the theory of convergent classes and a sufficient and necessary condition for a space to satisfy the first countability axiom is obtained.
出处
《中山大学研究生学刊（自然科学与医学版）》
1997年第4期1-3,共3页
Journal of the Graduates Sun YAT-SEN University(Natural Sciences.Medicine)
关键词
有向集
网
收敛类
Directed set
Net
Convergence classes
