δ-closure, θ-closure and generalized closed sets

Abstract

We study some new classes of generalized closed sets (in the sense of N. Levine) in a topological space via the associated δ-closure and θ-closure. The relationships among these new classes and existing classes of generalized closed sets are investigated. In the last section we provide an extensive and more or less complete survey on separation axioms characterized via singletons.

Keywords

• δ-closed
• θ-closed
• qr-closed
• separation properties