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

*Remark [#r8725ddc]
-semi-generalized open and [[generalized open]] are, in general, independent.

*Reference [#naf29589]
-Bhattacharyya Paritosh, Lahiri B. K., ''Semigeneralized closed sets in topology.'', Indian J. Math. 29 (1987), no. 3, 375-382 (1988).