Generalizations of Connected and Compact Sets by $d_\delta$-Closure Operator

Abstract

In this paper, we introduce two new concepts, namely, a subset being $d_\delta$-connected relative to a topological space, and a subset being $D_\delta$-closed relative to the space. The former is a generalization of the concept of a subset being $\theta$-connected relative to a space, and the latter is analogous to the $H(i)$ space.