Re: Motion P1788/M0013.04 - Comparisons

["Nate Hayes" <nh@xxxxxxxxxxxxxxxxx>]

Good question, John.

The purist in me might say (3).

But since P1788 has (so far) decided to allow unbounded intervals, the 
pragmatist in me might say (1).

I'd be interested to hear what others think.

Nate


----- Original Message ----- 
From: "John Pryce" <j.d.pryce@xxxxxxxxxxxx>
To: "stds-1788" <stds-1788@xxxxxxxxxxxxxxxxx>
Sent: Saturday, September 18, 2010 2:36 AM
Subject: Re: Motion P1788/M0013.04 - Comparisons


> P1788
>
> This is the third or fourth time I ask this question, but I don't recall 
> ever having an answer.
>
> Concerning the relation "is interior to", (\subset in Kulisch's notation), 
> what's the result of
>   [1,oo] is interior to [0,oo]
> ?
>
> Someone please say which of these is right:
> (1) It is false, because the endpoints of the "inside" set _must_ be 
> different from those of the "outside" one.
> (2) It is true, because what we want is "topologically interior to".
> (3) I couldn't care less, because this relation is only useful for bounded 
> intervals.
>
> Or, of course, something else.
>
> Answers from those with experience in writing interval software especially 
> welcome.
>
> John Pryce