Weak bases and Metrizability

A. M. Mohamad

Abstract

In this paper we investigate weak bases. We give a characterization of
weakly developable spaces and metrization theorems. The metrization
results are:
a space $X$ is metrizable if and only if $X$ has a $CWBC$--map
$g$ satisfying the following conditions:
begin {enumerate}
item $g$ is a pseudo--strongly--quasi--N--map;
item for any $A subseteq X, overline {A} subseteq bigcup
{g(n,x) : x in A }$;
end {enumerate}
a space $X$ is metrizable if and only if $X$ has a $CWBC$--map
$g$ satisfying the following conditions:
begin {enumerate}
item if $x in g(n,y_n)$, $y_n in g(n,x_n)$, $x_n in g(n,y_n)$
and $y_n in g(n,x)$ for all $n in N$, then $x_n$ converges to $x$;
item for any $A subseteq X, overline {A} subseteq bigcup
{g(n,x) : x in A }$.
end {enumerate}

Keywords
weakly developable; metrizable; weakly first countable; quasi--$G^*_{delta}$-diagonal.

Math Review Classification
Primary 54E30, 54E35

Last Updated

Length
8 pages

Availability
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