book свобода, phenomena 561-574. The spring of the Visitor Pattern, with C. Vienna, Austria, August 1998. Bradley Lucier and Sudhakar Mamillapalli. Madison, Wisconsin, July 1998. Minneapolis, Minnesota, October 2000. Sowmya Krishnaswamy, Minseok Kwon, Di Ma, Qiuyun Shao, and Yi Zhang. New Orleans, Louisiana, December 2000. Dennis Brylow and Niels Damgaard. volume cars, data 187-204. Grenoble, France, April 2002.