*Definition [#kd265615]
-Complements of [[γ-open]] sets are called γ-closed.

*Reference [#vbce4ac6]
-Basu, C. K.; Afsan, B. M. Uzzal; Ghosh, M. K., ''A class of functions and separation axioms with respect to an operation.'' (English summary), Hacet. J. Math. Stat. 38 (2009), no. 2, 103-118.