On weak forms of preopen and preclosed functions. (English) Zbl 1111.54011

The purpose of this paper is to introduce and study two new concepts of weakly preopen and weakly preclosed functions. Characterization theorems and basic properties for such functions are proved. These results are then used to show that images of weakly preclosed functions with strongly separated fibers are pre-Hausdorff and that inverse images of \(P\)-closed sets, by open weakly preclosed injective functions such that inverse images of points are quasi \(H\)-closed, are quasi \(H\)-closed.
Reviewer: Jan Paseka (Brno)


54C08 Weak and generalized continuity
54A40 Fuzzy topology
54C10 Special maps on topological spaces (open, closed, perfect, etc.)
54D10 Lower separation axioms (\(T_0\)–\(T_3\), etc.)
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