On upper and lower almost \(\beta\)-continuous multifunctions
Nasef and Noiri have introduced the notion of almost \(\beta\)-continuity. In the present paper the authors define the notion of upper (lower) almost \(\beta\)-continuous multifunctions. Several interesting characterizations are obtained and many properties of these multifunctions are studied by using for example \(\beta\)-(\(s\)-)closure, the graph multifunction, e.t.c. The authors offer various relationships between upper (lower) almost \(\beta\)-continuous multifunctions and upper (lower) \(\beta\)-continuous (or upper (lower) weakly \(\beta\)-continuous) ones. At the end, some properties of the product multifunction are thoroughly studied.
scientific article; zbMATH DE number 1355007