- GENERALIZED FRÉCHET-URYSOHN SPACES
- GENERALIZED FRÉCHET-URYSOHN SPACES
- ㆍ 저자명
- Hong. Woo-Chorl
- ㆍ 간행물명
- Journal of the Korean Mathematical Society
- ㆍ 권/호정보
- 2007년|44권 2호|pp.261-273 (13 pages)
- ㆍ 발행정보
- 대한수학회
- ㆍ 파일정보
- 정기간행물|ENG| PDF텍스트
- ㆍ 주제분야
- 기타
In this paper, we introduce some new properties of a topological space which are respectively generalizations of $Fr'{e}chet$-Urysohn property. We show that countably AP property is a sufficient condition for a space being countable tightness, sequential, weakly first countable and symmetrizable, to be ACP, $Fr'{e}chet-Urysohn$, first countable and semimetrizable, respectively. We also prove that countable compactness is a sufficient condition for a countably AP space to be countably $Fr'{e}chet-Urysohn$. We then show that a countably compact space satisfying one of the properties mentioned here is sequentially compact. And we show that a countably compact and countably AP space is maximal countably compact if and only if it is $Fr'{e}chet-Urysohn$. We finally obtain a sufficient condition for the ACP closure operator $[{cdot}]_{ACP}$ to be a Kuratowski topological closure operator and related results.