*Definition [#u56b7800]
-Let (X, T , E) be a [[soft space>soft topological space]] over X, then the members of T are said to be soft open sets in X.

*Reference [#y6a03573]
-Shabir Muhammad, Naz Munazza, ''On soft topological spaces.'' (English summary), Comput. Math. Appl. 61 (2011), no. 7, 1786-1799.