Miguel Caldas, Saeid Jafari, and Seithuti P. Moshokoa Rua M\'{a}rio Santos Braga, s/n, Oester Farimagsgade 5, Building 26, P.O. Box 392
Abstract : Nakaoka and Oda (\cite{CAL1} and \cite{DUN1}) introduced the notion of maximal open sets and minimal closed sets in topological spaces. In this paper, we introduce new classes of sets called maximal $\theta $-open sets, minimal $\theta $ -closed sets, $\theta $-semi maximal open and $\theta$-semi minimal closed and investigate some of their fundamental properties.
Keywords : topological space, maximal open sets, minimal closed sets, $ \theta $-open sets, $\theta$-semi maximal open sets
