Alessandro Fedeli
On the cardinality of functionally Hausdorff spaces

Comment.Math.Univ.Carolinae 37,4 (1996) 797-801.

Abstract:In this paper two new cardinal functions are introduced and investigated. In particular the following two theorems are proved: \par \noindent {(i)} If $ X$ is a functionally Hausdorff space then $|X| \leq 2^{fs(X) \psi _{\tau }(X)}$; \par \noindent {(ii)} Let $X$ be a functionally Hausdorff space with $fs(X) \leq \kappa $. Then there is a subset $S$ of $X$ such that $|S| \leq 2^{\kappa }$ and $X = \bigcup \{ cl_{\tau \theta }(A): A \in [S]^{\leq \kappa } \}$.

Keywords: cardinal functions, $\tau $-pseudocharacter, functional spread
AMS Subject Classification: 54A25

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