Re: DirectedInf
> Date: Sat, 09 Oct 2010 11:51:06 +0200
> From: Arnold Neumaier <Arnold.Neumaier@xxxxxxxxxxxx>
> To: Nate Hayes <nh@xxxxxxxxxxxxxxxxx>
> CC: Dan Zuras Intervals <intervals08@xxxxxxxxxxxxxx>,
> stds-1788@xxxxxxxxxxxxxxxxx
> Subject: Re: DirectedInf
>
> Nate Hayes wrote:
> > Arnold Neumaier wrote:
> >> After carefully checking the statements in the standard,
> >> I am sure that one can make things 754-conforming by defining the
> >> new concept of an interval-point format, which agrees with the
> >> floating-point format on finite reals but differs on the treatment
> >> of inf and NaN. Then none of the constraints on floating-point data
> >> apply for interval-point data.
> >>
> >> But the same hardware can be used with a switch of rounding modes,
> >> and the exceptions can be handled as required for fast interval support.
>
> > One thing that still worries me is that in Vienna Proposal it appears
> > the method requires that -0 and +0 are not aliases of each-other.
>
> Why is that an obstacle?
>
Well, you know I disapprove of creating new values for NaNs.
But as far as 754 is concerned, so long as the arithmetic
for zero is done as specified & +0 compares equal to -0,
I don't see a problem.
On the other hand, I'm not sure where in Vienna the concern
is written.
Nate, can you give me chapter & verse?
Dan