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Re: formatOfMidpoint()



On 14 Feb 2012, at 16:32, Vincent Lefevre wrote:
> On 2012-02-11 20:57:40 -0800, Dan Zuras Intervals wrote:
>> 	Under those circumstances any answer for
>> 	midpoint(Empty) is as good as any other.
>> 	Or as bad.  For if X = Empty what does
>> 	equation (22) mean?
>> 
>> 		X \subset [m-r,m+r]	(22)
>> 
>> 	where m = midpoint(Empty) & r = radius(Empty)?
>> 
>> 	It works for any midpoint but NaN.  But it
>> 	fails for NaN.
> 
> I think that Equation (22) should be considered only when it makes
> sense at Level 1, i.e. when the midpoint and radius are properly
> defined. For Empty, they aren't.
> 
> And what's important is when things don't make sense, the results
> should carry this information (there may be some exceptions, though):
> Empty for intervals, NaN for point values.

I agree.
John Pryce