for my $n (53..55) {
    my $max =   2**($n-1) - 1 ;
    my $min = -(2**($n-1)) ;

    printf "%4d: -%s..%s\n", $n, show($min), show($max) ;
  } ;

  sub show {
    my ($x) = @_ ;

    my $ms = int(abs($x)/2**32) ;
    my $ls = abs($x) - ($ms * 2**32) ;

    sprintf '0x%04X_%04X_%04X_%04X', ($ms >> 16), ($ms & 0xFFFF),
                                     ($ls >> 16), ($ls & 0xFFFF) ;
  } ;

##</code><code>##

  my $z = 0x0FED_CBA9_8765_4321 ;
  my $d = 9 ;

  printf " a = %20s * %d + i, for i = 0..%d\n", "$z", $d, $d ;
         # 12: 12345678901234567890 : +2345
  print  "  i:                a / $d : Error\n" ;
 
  foreach my $i (0..$d) {
    my $a = ($z * $d) + $i ;
    my $q = $a / $d ;

    printf " %2d: %20s : %+5d\n", $i, "$q", $q - ($z + int($i/$d)) ;
  } ;