Submitted on: 28 February 2009.
Revised on: 22 March 2009.
Accepted on: 03 May 2009.
___________________INTERNATIONAL JOURNAL OF COMPUTER MATHEMATICS
http://reply.papertrans.cn/2/133/13202/13202-32.png
http://reply.papertrans.cn/2/133/13202/13202-33.png
Submitted on: 27 June 1998.
Revised on: 15 August 1998.
Accepted on: 26 August 1998.
___________________INTERNATIONAL JOURNAL OF COMPUTER MATHEMATICS
http://reply.papertrans.cn/2/133/13202/13202-35.png
http://reply.papertrans.cn/2/133/13202/13202-36.png