Submitted on: 08 April 2004.
Revised on: 27 April 2004.
Accepted on: 21 May 2004.
Logical Methods in Computer Science
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http://reply.papertrans.cn/3/211/21023/21023-33.png
Submitted on: 08 December 2007.
Revised on: 29 December 2007.
Accepted on: 10 January 2008.
Logical Methods in Computer Science
http://reply.papertrans.cn/3/211/21023/21023-35.png
Submitted on: 17 September 2003.
Revised on: 28 October 2003.
Accepted on: 02 November 2003.
Logical Methods in Computer Science