Using the isomorphism from [3] between the category Pries of Priestley spaces and the category PStone of pairwise Stone spaces we construct a Vietoris hyperspace functor on the category PStone related to the Vietoris hyperspace functor on the category Pries [4, 18, 24]. We show that the coalgebras for this functor determine a semantics for the positive fragment of modal logic. The sole novelty ...

In this paper, some new types of regularity axioms, namely pairwise quasi-regular, semi-regular, pseudo regular and are defined studied in both ech fuzzy soft bi-closure spaces ( bicsp’s) their induced bitopological spaces. We also study the relationships between them. show that all these hereditary property is satisfied under closed fs bi-csubsp . Furthermore, we define normality semi-normal, ...

I would like to thank the organizers of the UNISA Topology Workshop, Koena Rufus Nailana and Sergio Salbany, for doing an excellent job acquiring funding, making arrangements, and especially for assembling an enthusiastic group of participants. An ordered topological space (X, τ,≤) is a set X with a topology τ and a partial order ≤. We usually assume some forms of compatibility between the topo...