Search Results

You are looking at 1 - 2 of 2 items for :

• "Star countable"
• Refine by Access: All Content
Clear All

Some remarks on almost star countable spaces

Studia Scientiarum Mathematicarum Hungarica
Author:
Yan-Kui Song

A space X is almost star countable (weakly star countable) if for each open cover U of X there exists a countable subset F of X such that \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage{bbm} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $\bigcup {_{x \in F}\overline {St\left( {x,U} \right)} } = X$ \end{document} (respectively, \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage{bbm} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $\overline {\bigcup {_{x \in F}} St\left( {x,U} \right)} = X$ \end{document} . In this paper, we investigate the relationships among star countable spaces, almost star countable spaces and weakly star countable spaces, and also study topological properties of almost star countable spaces.

Open access

On star Lindelöf spaces

Studia Scientiarum Mathematicarum Hungarica
Authors:
Wei-Feng Xuan
and
Yan-Kui Song

A ⊂ X   such that   S t ( A , U ) = X . It is evident that every star countable space is star Lindelöf, and every star Lindelöf space is star countable extent ([ 12 ]). It is well known and easy to prove that every topological space with countable

Restricted access