Fahad Alsharari, Ahmed O. M. Abubaker,
Islam M. Taha
AIMS Mathematics 2025, 10(3): 5285-5306
Published: 15 March 2025
In this paper, we defined and discussed a new class of fuzzy soft open (FS-open) sets, called -fuzzy soft -open ( -FS- -open) sets in fuzzy soft topological spaces (FSTSs) based on fuzzy topologies in the sense of Šostak. The class of -FS- -open sets is contained in the class of -FS- -open sets, and contains all -FS-semi-open and -FS-pre-open sets. However, we introduced the closure and interior operators with respect to the classes of -FS- -closed and -FS- -open sets, and studied some of their properties. Thereafter, we defined and studied some new FS-functions using -FS- -open and -FS- -closed sets, called FS- -continuous (respectively (resp. for short) FS- -irresolute, FS- -open, FS- -irresolute open, FS- -closed, and FS- -irresolute closed) functions. The relationships between these classes of functions were discussed with the help of some illustrative examples. We also explored and established the notions of FS-weakly (resp. FS-almost) -continuous functions, which are weaker forms of FS- -continuous functions. We showed that FS- -continuity FS-almost -continuity FS-weak -continuity, but the converse may not be true. After that, we presented some new types of FS-separation axioms, called -FS- -regular and -FS- -normal spaces using -FS- -closed sets, and investigated some properties of them. Finally, we introduced a new type of FS-connectedness, called -FS- -connected sets using -FS- -closed sets.