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A NOTE ON SPACES WHICH HAVE COUNTABLE TIGHTNESS
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 Title & Authors
A NOTE ON SPACES WHICH HAVE COUNTABLE TIGHTNESS
Hong, Woo-Chorl;
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 Abstract
In this paper, we introduce closure operators []c and []a on a space and study some relations among []c, []a and countable tightness. We introduce the concepts of a strongly sequentially closed set and a strongly sequentially open set and show that a space X has countable tightness if and only if every strongly sequentially closed set is closed if and only if every strongly sequentially open set is open. Finally we find a generalization of the weak Frchet-Urysohn property which is equivalent to countable tightness.
 Keywords
countable tightness;c(a)-closure operators;strongly sequentially closed;strongly sequentially open;weak Frchet-Urysohn property;
 Language
English
 Cited by
1.
ON SPACES WHICH HAVE COUNTABLE TIGHTNESS AND RELATED SPACES,;

호남수학학술지, 2012. vol.34. 2, pp.199-208 crossref(new window)
1.
ON SPACES WHICH HAVE COUNTABLE TIGHTNESS AND RELATED SPACES, Honam Mathematical Journal, 2012, 34, 2, 199  crossref(new windwow)
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