> my $a = 1.000000000000001e0; my $b = 1e0; $a - $b
0
> $a - 1
1.11022302462516e-15
> $b - 1
1.11022302462516e-15
> $a.WHERE
4405787632
> $b.WHERE
4405787632
> 1.000000000000001e0 == 1e0
True