1Department of Mathematics, Jordan University, Amman-Jordan. E-mail: atallafha@hotmail.com
2Department of Mathematics, Qatar University, P.O.Box 2713, Doha, Qatar. E-mail: albsoulaaa@hotmail.com
3Department of Mathematics, Yarmouk University, Irbid, Jordan.
1991 Mathematics Subject Classification: Primary 54D10, 54D99; Secondary 54F65, 54G20.
In this paper we ordered a countable set by means of closure. As an application of this technique we obtained some characterizations of T0 and T1–spaces. Also, we give another proof of the result of Fitzpatrick, White and Zhou in [3] which states that every CDH space is T1, throughout closurely orderd countable sets. Moreover, the technique used in the proof is programmable and expected to has applications in computer sciences.
COP, COCS, CDH spaces, lower separation axioms
