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| Volume 28 • Number 2 • 2006 |
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On Relative 1½-StarLindelöfness
Yan-Kui Song, Guang-Fa Han and Pi-Yu Li
Abstract.
A subspace Y of a space X is strongly 1½-starLindelöf in X if for every open
cover U of X, there
exists a countable subset V of
U such that
V∩Y≠∅ for each
V∈V and
Y⊆S t(∪V,U), where St(∪V,U)=∪{U∈U:U∩∪V≠∅}.
A subspace Y of a space X is ½-starLindelöf in X if for every open cover
U of X, there exists a
countable subset V of U such that Y⊆S
t(∪V,U).
In this paper, we give an example to show the difference
between relative strongly 1½-starLindelöfness
and relative 1½-starLindelöfness.
2000 Mathematics Subject Classification: 54A25, 54D20.
Full text: PDF
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