# FALSE-on-0        (bad)
% perl -e 'while($x = 0)       {sleep print "Hello\n"}'
% perl -e 'while(($x = 0))     {sleep print "Hello\n"}'
% perl -e 'while((($x = 0)))   {sleep print "Hello\n"}'
% perl -e 'while(((($x = 0)))) {sleep print "Hello\n"}'