On a class of sets between a-open sets and gδ-open sets

Abstract

In this paper, a new class of sets called Da-open sets are introduced and investigated with the help of gδ-open and δ-closed sets. Relationships between this new class and other related classes of sets are established and as an application Da-continuous functions have been dened to study its properties in terms of Da-open sets.Finally, some properties of Da-closed graph and (D.a)-closed graphs are investigated.

Keywords

• a-open set,δ-open set,gδ-open,da-open set,da-closed set