1Department of Mathematics, College of Education for Pure Sciences, University of Mosul, Mosul, Iraq.
2Department of Mathematics College of Education University of Mosul, Mosul, Iraq
Abstract
In this paper, we define ii-open set in bitopological space as follows: Let (, , ) be a bitopological space, a subset A of is said to be ( – ii- open set ) if there exist U,V ≠ and U,V such that:
A=int1(U) or A=int2 (V) A or A
We study some characterizations and properties of this class. Also, we explain the relation between ii- open sets and open sets, i-open sets and α-open sets in bitopological space. Furthermore, we define ii- continuous mapping on bitopological spaces with some properties.