Some topological properties of e-space and description of τ-closed sets

In this paper we study preserving properties of the e-space under the normal functors ?n, SPn and expn. We prove that when a topological space X is an e-space, the spaces Xn, SPnX and expnX are also e-spaces. We also study the behavior of e-continuity of mappings, proving that the functors ?n, SPn and expn preserve the e-continuity. In addition, we introduce the notions of ?-boundary points, ?-cluster points and ?-boundary of a set and study many of their properties.