use FloatingPoint::Helper -tolerance => 0.0001;
# Ok, not a good module name...
my $a = FloatingPoint::Helper->float(12e-4);
my $b = FloatingPoint::Helepr->float(1.2e-3);
if ($a > $b) {
    print "really greater...\n";
} elsif ($a < $b) {
    print "really lesser...\n";
} else {
    print "almost equal...\n";
}