*Definition [#g699f94f]
-Let  (X, τ) be a topological space. A subset S ⊆ X is called semi-closed if the complement X-B is a semi-open set.

*Reference [#r45f5936]
-Bhattacharyya Paritosh, Lahiri B. K., ''Semigeneralized closed sets in topology.'', Indian J. Math. 29 (1987), no. 3, 375-382 (1988).