The inequality |X|≤2χ(X) has been proved to be true for both the class of Lindelöf spaces (Arhangel'skii, 1969 [1]) and that of H-closed spaces (Dow and Porter, 1982 [6]), by different arguments. We present a common weakening of the Lindelöf and H-closed properties which allows us to give a unified proof of these two theorems.

A useful common weakening of Lindelöf and H-closed

Bella, Angelo
2019

Abstract

The inequality |X|≤2χ(X) has been proved to be true for both the class of Lindelöf spaces (Arhangel'skii, 1969 [1]) and that of H-closed spaces (Dow and Porter, 1982 [6]), by different arguments. We present a common weakening of the Lindelöf and H-closed properties which allows us to give a unified proof of these two theorems.
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/20.500.11769/375487
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