Geodesic
On the Cardinality of Urysohn Spaces
Canadian mathematical bulletin, Tome 31 (1988) no. 2, pp. 153-158

Voir la notice de l'article provenant de la source Cambridge University Press

In this paper some cardinal inequalities for Urysohn spaces are established. In particular the following two theorems are proved:(i)If where [A]θ denotes the θ-closed hull of A, i.e., the smallest θ-closed subset of X containing A;(ii), where aL(X, X) is the smallest cardinal number m such that for every open cover of X there is a subfamily for which
DOI : 10.4153/CMB-1988-023-4
Mots-clés : Cardinal functions, θ-closed sets, almost Lindelöf degree, Primary, 54A25, Secondary, 54D20 
Bella, A.; Cammaroto, F. On the Cardinality of Urysohn Spaces. Canadian mathematical bulletin, Tome 31 (1988) no. 2, pp. 153-158. doi: 10.4153/CMB-1988-023-4
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