On RW-Closed Sets in Topological Spaces

In this paper, a new class of sets called regular w-closed (briefly rw-closed) sets in topological spaces is introduced and studied. A subset A of a topological space (X, tau) is called rw-closed if U contains closure of A whenever U contains A and U is regular semiopen in (X, tau). This new class of sets lies between the class of all w-closed sets and the class of all regular g-closed sets. Some of their properties are investigated.