Some remarks on almost Lindel{ö}f spaces and weakly Lindel{ö}f spaces

Authors

  • Yan-Kui Song Institute of Mathematics, School of Mathematics and Computer Sciences, Nanjing Normal University, Nanjing 210097, P. R.China Author
  • Yun-Yun Zhang Institute of Mathematics, School of Mathematics and Computer Sciences, Nanjing Normal University, Nanjing 210097, P. R.China Author

Keywords:

Lindel{ö}f, almost Lindel{ö}f, weakly Lindel{ö}f

Subjects:

54D20, 54E18

Abstract

A space $X$ is almost Lindel{ö}f (weakly Lindel{ö}f) if for everyopen cover $\Cal U$ of $X$, there exists a countable subset $\Cal V$of $\Cal U$ such that $\bigcup\{\overline{V}:Vın \Cal V\}=X$(respectively, $\overline{\bigcup\Cal V}=X$). In this paper, weinvestigate the relationships among almost Lindel{ö}f spaces,weakly Lindel{ö}f spaces and Lindel{ö}f spaces, and alsostudy topological properties of almost Lindel{ö}f spaces and weakly Lindel{ö}f spaces.

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Published

2010-01-15