On Urysohn, almost regular and semiregular functions. (English) Zbl 0822.54007

The authors define and study \(T_0\)-, \(T_1\)-, Hausdorff, etc. maps. For example, a map \(f: X\to Y\) is Hausdorff iff whenever \(x\neq y\) and \(f(x)= f(y)\) the points \(x\) and \(y\) have disjoint neighbourhoods. The obvious relations between these notions are established.
Reviewer: K. P. Hart (Delft)


54C10 Special maps on topological spaces (open, closed, perfect, etc.)
54A99 Generalities in topology