Abstract

We deepen the study of two known neighborhood structures, which here will be called fk-neighborhood structures and fq-neighborhood structures, in the context of Šostak fuzzy topological spaces. In particular, we characterize fuzzy topologies by fk-neighbor-hood structures. Moreover we introduce and discuss the notions of fk-neighborhood prestructure and fm-neighborhood structure in the same context. At last we prove that the three neighborhood structures mentioned above are equivalent.