bug :-
	write('\
Copyright (C) 2001-2003 Roberto Bagnara <bagnara@cs.unipr.it>\n\
this program is free software, covered by the GNU General Public License,\n\
and you are welcome to change it and/or distribute copies of it\n\
under certain conditions.\n\
Type "copying" to see the conditions.\n\
There is ABSOLUTELY NO WARRANTY for this program.\n\
Type "warranty" for details.\n').
