Re: Motion P1788.1/M004.01
On Tue, 17 May 2016 15:25:01 +0200, Vincent Lefèvre wrote, replying to me:
(regarding exact zero vs inexact zero, i.e. underflow)
> > Unfortunately 754 has no easy way to track the distinction.
> This is not possible: the problem is undecidable (this is basically
> the TMD on an exact case).
Richardson's theorem does not apply to IEEE 754 (my context), since
only finite sets of rational numbers are involved -- no Pi, log 2, or
(to mention the one reamining requirement after some of the original
ones were found to be inessential) an exact sin() function.
To what extent it applies to 1788 (Intervals, where irrationals are
genuine members), I don't know.
> The best that one can do is to track exactness.
That's in fact all I was talking about.
Michel.
---Sent: 2016-05-17 15:43:08 UTC