Re: Comparisons and decorations, part 2
> Date: Tue, 28 Sep 2010 14:26:23 +0200
> From: Arnold Neumaier <Arnold.Neumaier@xxxxxxxxxxxx>
> To: Dan Zuras Intervals <intervals08@xxxxxxxxxxxxxx>,
> 1788 <stds-1788@xxxxxxxxxxxxxxxxx>
> Subject: Re: Comparisons and decorations, part 2
>
> Dan Zuras Intervals wrote:
>
> > Then let me suggest that there exist a
> > decoration for empty.
> >
> > Or, at least, some combination of the
> > existing decorations that implies empty.
> >
> > That way we do not NEED a representation
> > for empty within the interval part of a
> > 1788 interval.
> >
> > And we will have anything + empty = empty
> > fall out to be both fast & easy no matter
> > what we use for empty so long as the
> > decoration makes it so.
>
> Since bare[1,1]/bare[0,0] or sqrt(bare[-2,-1]) must be empty,
> this conflicts with the need of a fast mode for arithmetic
> operations for bare intervals.
>
>
> Arnold Neumaier
>
On the contrary, it is consistent with that.
I was discussing fast & easy intervals for
which the interpretation of empty is to be
found in the decoration.
That you might need some further restriction,
say your favorite [NaN,NaN], for bare intervals
is still consistent.
And, should we feel that it is the appropriate
way to go within that context, I have no
objection.
Dan