On generalized Hausdorff semicontinuity of multifunctions. (English) Zbl 0798.54022

Náther, Ondrej

Acta Univ. Carol., Math. Phys. 33, No. 2, 109-114 (1992).

The paper deals with a certain characterization of the generalized Hausdorff semicontinuity of multifunctions. The characterization is analogous to the one given in [G. Beer, Hyperspaces of a metric space: an overview, Publ. del. Dip. di Mat. et Appl., Napoli]. Since there are many types of generalizations of the continuity it seems to be useful to use such a type which includes the other ones. It was done in [C. Bruteanu and I. Tevy, Rev. Roum. Math. Pur. Appl. 18, 121-135 (1973; Zbl 0254.26004)], where the so called \({\mathcal S}\)- continuity is introduced with the help of the concept of a local sieve. The same procedure is followed in this paper. In the second part some consequences of the characterization for a quasicontinuity are given.

MSC:

54C60	Set-valued maps in general topology
54C08	Weak and generalized continuity

Citations:

Zbl 0254.26004