Re: Proposal for a new structure of the standard
> From: John Pryce <j.d.pryce@xxxxxxxxxxxx>
> Subject: Proposal for a new structure of the standard
> Date: Mon, 12 Jul 2010 08:57:22 +0100
> To: P1788 <stds-1788@xxxxxxxxxxxxxxxxx>
>
> P1788
>
> =46rom the introduction to the attached position paper:
>
> > There has been disagreement in the P1788 group for some time about the =
> proper status of interval formats such as mid-rad, that are not based on =
> storing the lower and upper bounds. There has also been criticism of the =
> current draft text as too prescriptive: why go beyond a minimal =
> specification that ensures the Fundamental Theorem of Interval =
> Arithmetic (FTIA) holds? In response there have been discussions over =
> several weeks, mainly between Corliss, Hayes, Kearfott, Keil, Pryce and =
> Zuras. These have produced a revised approach to the standard. I present =
> it here and aim to propose it as a motion shortly.
> >
> > . . .
> >
> > All interval datatypes are equal,
> >
> > . . .
> >
> > I am hastening to get something out before I go on holiday 13=9627 =
> July, so I submit this as work in progress. I believe the basic =
> structure is sound but various issues need further discussion before =
> there is a firm motion.
>
> Best wishes
>
> John Pryce
>
I like it.
I like the substance of it.
I like the language of it.
I like the fact that it makes all conforming interval
types equal. Indeed, the fact that you hardly mention
either type & remain largely at the level of finite
sets of Intervals makes that very clear.
I like the clarity of your exposition of the uniqueness
problem for implicit intervals. Also entirely at the
set theoretic level. Very nice.
I like the fact that you have clearly defined the hull()
problem but left the solution up to the implementers.
Again, entirely without reference to the representation
at level 3. Whether or not they want to standardize on
that solution may be one of the questions to be answered
in the fullness of time.
One nit: in 4.1 on page 3. that other standard is known
as LIA, not LTIA. No need to change it now. That can
wait until you get back.
I like your exposition of the rationale.
And I like your summary of the questions still pending.
If our discussion can proceed under this framework I
think we can make progress now.
Of course, we will all have different opinions (myself
included) so it will be a lively discussion.
But when has it been otherwise? :-)
Enjoy your vacation,
Dan