Characterization of some peculiar topological spaces via \({\mathcal A}\)- and \({\mathcal B}\)-sets
A subset \(S\) of a topological space \(X\) is called an \(A\)-set (resp. a \(B\)-set) if \(S\) is the intersection of an open and a regular closed set (resp. the intersection of an open and a semi-closed set). In this paper the author provides characterizations of the classes of submaximal spaces, partition spaces, indiscrete spaces, discrete spaces and extremally disconnected spaces via \(A\)-sets and \(B\)-sets.
scientific article; zbMATH DE number 878087
scientific article