*Definition [#m5f65c11]
-A topological space (X,τ) is said to be strong T_D if for each point x of X, the [[derived set]] {x}' is a finite union of closed sets, the intersection of the non-empty members of which is empty.

*Property [#e4a9aad9]
-A [[normal]] strong T_D space is [[T_4]] space.

*Reference [#x6ac1ba1]
-Singal, Asha Rani, ''Remarks on separation axioms.'' (English) [A] General Topology Relations modern Analysis Algebra, Proc. Kanpur topol. Conf. 1968, 265-296 (1971).