On the class of contra \(\lambda\)-continuous functions. (English) Zbl 1174.54349
A set \(A\) in a topological space \(X\) is called a \(\Lambda\)-set if it is the intersection of all its open supersets. A set which is the intersection of a \(\Lambda\)-set and a closed set is called \(\lambda\)-closed. The class of contra \(\lambda\)-continuous functions (the preimage of each open set is \(\lambda\)-closed) is introduced and several properties of these functions are investigated.
Reviewer: Ljubiša D. Kočinac (Aleksandrovac)
MSC:
54C10 | Special maps on topological spaces (open, closed, perfect, etc.) |
54D10 | Lower separation axioms (\(T_0\)–\(T_3\), etc.) |