Re: Reasons (not) to vote Motion 27: NO
On 2011-08-17 15:37:05 +0200, Arnold Neumaier wrote:
> On 08/17/2011 03:43 AM, Vincent Lefevre wrote: [in: Motion 26: NO]
> >5.8.4 and 5.8.5 are very complicated and difficult to understand, and
> >without better explanations, I'm not convinced that they are correct.
> >Moreover 5.8.5 seems to be wrong on the following example:
> > * xx = [-2,-1]
> > * yy = Empty
> > * f(x,y) = sqrt(x) + y
> >One gets:
> > * The decoration of xx from domain(xx) is bnd.
> > * The decoration of yy from domain(yy) is emp.
> > * For zz = sqrt((xx,bnd)), p_emp(sqrt,xx) holds, so that one chooses
> > e = emp. Thus d = min{emp,bnd} = emp.
> > * For zz + yy, if one applies (Eval3) directly as said in 5.8.5:
> > one chooses e = con. Then d = min{con,emp,emp} = emp. But since
> > the box (xx,yy) is empty, according to (8), the decoration of
> > f(xx,yy) must be > emp, leading to a contradiction. So, it seems
> > that (Eval1) was necessary here.
>
> Note that (as already discussed last year) before any function evaluation
> with decorations, domain must be called to set the correct initial
> decorations, which is designed to take care of situations with some empty
> input. Thus the specification is OK.
This is exactly what I've done above:
* The decoration of xx from domain(xx) is bnd.
* The decoration of yy from domain(yy) is emp.
If you consider the steps described in 5.8.5, how can ein be generated?
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Vincent Lefèvre <vincent@xxxxxxxxxx> - Web: <http://www.vinc17.net/>
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