几乎次亚紧和几乎强次亚紧空间

Nearly submetacompact spaces and nearly strongly submetacompact spaces

证明了几乎次亚lindelf、可数紧度的可数紧X是紧空间.定义了几乎强次亚紧空间,给出了它的一个刻画,并证明了几乎强次亚紧、可数紧T3-空间是紧空间.

A countable compact and nearly submeta - lindeloef space with countable tightness are proved to be compact. The nearly strongly submetacompact space is defined and one of its characterizations is given. The nearly strongly submetacompact and the countable compact T3-space are proved to be compact.