\author{ Guido van Rossum \\ Corporation for National Research Initiatives (CNRI) \\ 1895 Preston White Drive, Reston, Va 20191, USA \\ E-mail: {\tt guido@CNRI.Reston.Va.US}, {\tt guido@python.org} } \date{May 8, 1997 \\ Release 1.5a3} % XXX update before release!