定義
In topological space, a subset A is said to be g-open (generalized open) if for every closed set F, the interior of A contains F whenever A contains F.
参考
K. Balachandran, P. Sundram and H. Maki, On generalized continuous maps in topological spaces, Mem. Fac. Sci. Kochi Uni. Ser A Math. 12 (1991), 5-13.