*Definition [#g8ed52b0]
A subset U of a topological space X is called ν-open if there is a [[regular open]] subset V of X such that V⊂U⊂cl(V).
*Reference [#p0f01161]
S. Balasubramanian, C.Sandhya and P.Aruna Swathi Vyjayanthi, ''Note on Regularity and ν-compactness'', Int. J. Contemp. Math. Sciences, Vol. 5, (2010) no. 16, 777-784