Some variants of normality in relative topological spaces


Sehar Shakeel Raina, A K Das




With each topological property P one can associate a relative version of it formulated in terms of the location of Y in X in such a natural way that when Y coincides with X, then this relative property coincides with P. Arhangel'skii and Genedi introduced this concept of relative topological properties in 1989. The concept of mild normality or κ-normality was introduced independently by Singal and Singal in 1973 and ˘ S˘ cepin in 1972. A few years earlier in 1969, Singal and Arya studied the concept of almost normality. V. Za ˘ icev in 1968 introduced the concept of quasi normal spaces while π-normality was studied by Kalantan in 2008. In this paper we study these variants of normality in a relative sense.