The further unified theory for modifications of λ-closed sets and gΛ-sets using minimal structures

摘要

We introduce and study two new notions of sets called (Λ, mn)-closed sets and gΛ _mn -sets, which are defined on a nonempty set with two minimal structures. These sets enables us to unify modifications of λ-closed sets [1] and generalized Λ-sets [15], respectively. Moreover, we give a new characterization of the class of mn-T _1/2 [17] by using gΛ _mn -sets. Keywords m-structure - (Λ, mn)-closed - mng-closed - gΛ _mn -set Mathematics Subject Classification (2000) 54A05 - 54A10 - 54D10