Department of Mathematics, Shangqiu Teacher's College, Shangqiu 476000, China; College of Mathematics and Information Science, Henan University, Kaifeng 475001, China
About author: LIANG Hong-liang(1963-),male,native of Zhecheng,Henan,an associate professor of Shangqiu Teacher's College,M.D.S.,engages in general topology.
Supported by:
Supported by Financial Aid Program of the Young Core Teacher of Higher Institution of Henan Province(2003100);