[Haskell-cafe] smallest double eps

[Chad Scherrer]

>
> Hang on, hang on, now I'm getting confused.
>
> First you asked for the smallest (positive) x such that
>     1+x /= x
> which is around x=4.5e15.
> Then Joachim wondered if you wanted
>     1+x /= 1
> which is around x=2.2e-16.
> But not you claim to be looking for the smallest positive number that
> a Double can represent.  Which is a totally different beast.  The
> smallest possible Double depends on if you want to accept
> denormalized numbers or not.  If you don't, then it's about x=4.5e-308.
>
> Now what is the number you are looking for?
>
>         -- Lennart
>

This is the point I was confused about also. Joachim seemed to be
correcting what might have been a misstatement of the problem.