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Re: Neumaier-Pryce proposed decoration system (v03.2)

John, Nate,
My position is that the case ein should be merged with safe by removing the restriction that for saf the input is not empty; 


BTW bnd is not a level 1 concept
Any continuous function is bounded
if f (x) == 1/x

f ([-1, -0.1]) = ([-10,-1], saf)
f(-1,0]) = ((-infty, -1), con)
bnd might be a useful concept at level 2 to distinguish between the representation of the level one intervals [0,1^10000] and [0,+infty) 

But even in that case con , daf and def are enough

Dominique


John Pryce a e'crit :

Nate

On 14 Jun 2011, at 05:18, Nate Hayes wrote:

One thing in v3.02 that puzzles me is the introduction of the decoration
"ein" as the "worst" decoration of the linear quality order (5).
...
It was in some offline discussions with the Gang of Ten a month or two later
that Dominique suggested arithmetic operations on empty input should give
the best decoration, not the worst.



I was also minded to make it the "best", for reasons I put forward in the emails you mentioned, but Arnold at time of circulating v03.2 favoured "worst". He is currently checking the FTDIA proof and updating it to the new set of decorations. Let's see what he comes up with.

However: though the difference between best and worst seems somewhat extreme, it is also possible this is not a serious show-stopper. ein is rather an "outlier" as properties go, so a version of FTDIA may exist with either choice of ein's position. I am suffering from FTDIA-fatigue at present, so prefer to wait and check someone else's work.

John Pryce





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