Between semi-closed and GS-closed sets

In this paper, we introduce the concept of strongly generalized semi- closed (= g*s – closed) sets, strongly generalized semi-open (= g*s – open) sets and strongly semi-T1/2-spaces (= st. semi-T1/2) which are stronger forms of gs-closed sets, gs–open sets and semi-T1/2 spaces respectively. Furthermore, we study some of their properties.(2000) Math. Subject Classification. 54C05.