#!/usr/bin/env perl
use strict;
use warnings;
my $finish = shift || 2.0;
my $format = shift || '%.17g';
die if +$finish == 0;
my $d = $finish / 2;
my $f = $d;
for (0..53) {
    my $s = '' .  $d;
    die sprintf "0+'$s' != $format", $d if +$s != $d;
    print sprintf "%s = $format\n", $s, $d;
    last if $d == $finish;
    $f /= 2, $d += $f
}