*Definition [#q1d77721]
-A space (X,τ) is called pre-T_2 iff to each pair of distinct points x, y of X, there exists a pair of disjoint [[pre-open]] sets one containing x and the other containing y.

*Property [#vc6c241d]
-Every pre-T_2 space is [[pre-US]].

*Reference [#x5203e70]
-Athisaya Ponmani, S.; Lellis Thivagar, M., ''Another form of separation axioms.'' ,  (English) [J] Methods Funct. Anal. Topol. 13, No. 4, 380-385 (2007).