Let \(X\) be a topological space. A subset \(A\subseteq X\) is a \(G_\delta\) set if \(A\) is a countable intersection of open subsets of \(X\).
What is a $G_\delta$ set?
$G_\delta$ sets
FD-HGESN
FD-HGESN
Let \(X\) be a topological space. A subset \(A\subseteq X\) is a \(G_\delta\) set if \(A\) is a countable intersection of open subsets of \(X\).