eng Ansari Education and Research Society Journal of Ultra Scientist of Physical Sciences April 2010 22 1 323 332 jusps-A 1061 article MRADUL DIXIT, 1 MANOJ GARG (garg_manoj1972@yahoo.com.in) 2 P.K. TRIPATHI 1 Department of mathematics , D.A.V., (PG) College, Kanapur U.P. (INDIA) Department of Mathamatics, Nehru (PG) College, Chhibramau, Kannoj U.P.) INDIA <p style="text-align: justify;">In this paper we introduce -closed sets¹⁹ in bitopological spaces. Properties of these sets are investigated and we introduce two new bitopological spaces (i, j)-&nbsp;spaces and (i, j)-spaces as applications. Further we introduce and study -continuous maps¹⁹ and -irresolute maps¹⁹ in bitopological spaces.<br /> &nbsp;</p> https://www.ultrascientist.org/paper/1061/ closed sets spaces continuity irresoluteness