strong T_D

Definition

• 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

• A normal strong T_D space is T_4? space.

Reference

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