Submitted on: 16 May 2004.
Revised on: 27 June 2004.
Accepted on: 16 July 2004.
SEMIGROUP FORUM
Submitted on: 05 April 2004.
Revised on: 21 April 2004.
Accepted on: 10 May 2004.
SEMIGROUP FORUM
http://reply.papertrans.cn/3/278/27770/27770-23.png
Submitted on: 16 October 2011.
Revised on: 29 November 2011.
Accepted on: 21 December 2011.
SEMIGROUP FORUM
http://reply.papertrans.cn/3/278/27770/27770-25.png
Submitted on: 24 August 2007.
Revised on: 23 September 2007.
Accepted on: 08 October 2007.
SEMIGROUP FORUM---SPRINGER
Submitted on: 13 December 2023.
Revised on: 10 January 2024.
Accepted on: 18 January 2024.
SEMIGROUP FORUM
http://reply.papertrans.cn/3/278/27770/27770-28.png
Submitted on: 24 February 2008.
Revised on: 04 April 2008.
Accepted on: 22 April 2008.
SEMIGROUP FORUM
http://reply.papertrans.cn/3/278/27770/27770-30.png