RE: motioin43 amended
To me (and I guess to Baker), the notation [-inf, +inf] implies that we use extended reals and include -inf and +inf as explicit elements, just like [0,1] means that the interval explicitly includes 0 and 1. This is how math papers usually handle this situation.
and this is NOT what we intend, since we do not plan to have +inf and -inf as elements of our sets.
-----Original Message-----
From: stds-1788@xxxxxxxx [mailto:stds-1788@xxxxxxxx] On Behalf Of Vincent Lefevre
Sent: Wednesday, April 24, 2013 8:50 AM
To: stds-1788@xxxxxxxxxxxxxxxxx
Subject: Re: motioin43 amended
On 2013-04-24 08:03:41 -0600, Kreinovich, Vladik wrote:
> Not really, since (-inf, +inf) is clearly a closed set, I agree with
> Baker on this
Not if one were working on the extended reals, where it would just be open.
And [-inf, +inf] has the advantage to avoid differentiating the cases where a bound is finite or not.
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Vincent Lefèvre <vincent@xxxxxxxxxx> - Web: <http://www.vinc17.net/> 100% accessible validated (X)HTML - Blog: <http://www.vinc17.net/blog/>
Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)