Re: Neumaier-Pryce proposed decoration system (v03.2)
On Wed, June 15, 2011 17:48, Dominique Lohez wrote:
>
> My position is that the case ein should be merged with safe by removing
> the restriction that for saf the input is not empty;
That's what we had before the discussion about empty input.
> BTW bnd is not a level 1 concept
> Any continuous function is bounded
> if f (x) == 1/x
f(x)=x is not bounded on [0,Inf], whereas f(x)=1/(1+x) is.
The complicated rule stated in the draft is needed to make sure
that [0,Inf]_bnd =sqr([0,realmax]_bnd) propagates correctly under
another squaring.
With the simplified rule one gets sqr([0,Inf]_bnd)=[0,Inf]_saf only.
Thus some information is lost. Thus if we want the simplified rule
then we should not track boundedness at all.
Arnold Neumaier