COVERING PROPERTIES BY (a)-SEMI-OPEN SETS IN (a)TOPOLOGICAL SPACES

Abstract

In this paper, we study the properties of $\left(a\right)$-semi-compact, $\left(a\right)$-semi-Lindelöf and $\left(a\right)$-semi-Menger in $\left(a\right)$topological spaces by using $\left(a\right)$-semi-open sets. We investigate the relationships of these properties with the other known covering properties. Further, we construct several examples to discuss the relationships between various covering properties.