% stephan@labaule (/home/stephan) %
% perl -Mbignum -e 'print 10**-1.0'       
NaN
% stephan@labaule (/home/stephan) %
% perl -Mbignum -e 'print 10.0**-1.0'
NaN
% stephan@labaule (/home/stephan) %
% perl -Mbignum -e 'print 10**-1'     
NaN