Submitted on: 26 February 1998.
Revised on: 02 June 1998.
Accepted on: 16 June 1998.
___________________European Journal for Philosophy of Science
Submitted on: 23 October 2003.
Revised on: 03 February 2004.
Accepted on: 03 April 2004.
___________________European Journal for Philosophy of Science
http://reply.papertrans.cn/1/91/9079/9079-23.png
http://reply.papertrans.cn/1/91/9079/9079-24.png
http://reply.papertrans.cn/1/91/9079/9079-25.png
http://reply.papertrans.cn/1/91/9079/9079-26.png
http://reply.papertrans.cn/1/91/9079/9079-27.png
http://reply.papertrans.cn/1/91/9079/9079-28.png
http://reply.papertrans.cn/1/91/9079/9079-29.png
http://reply.papertrans.cn/1/91/9079/9079-30.png