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Re: C language binding of P1888 operations, especially min and max

On 10/6/2013 5:04 PM, Kreinovich, Vladik wrote:

In line with all other operations of interval arithmetic, a natural idea for max(A,B) for two intervals A and B should be the set of all possible values max(a,b) when a is in A and b is in B. In this case, max([al,au],[bl,bu]) = [max(al,bl),max(au,bu)]. An example of A = [0,2] and B = [1,1] for which we get max(A,B) = [1,2], shows that this can be neither A not B

Yes, that would be the natural extension.
but if bl<bu<al<au, then the max would be [al,au]. Is it newly constructed, or just A? 
if  bl=al  and bu=au  is it newly constructed, just A, or just B?
Perhaps it doesn't matter if all operations have an implicit or explicit target, e.g. 
call double_max_interval(double_target, A, B)  where the result
is copied into the provided target space.
I'm thinking more in the framework of a functional language, or at least a language in which it would be natural to return (pointers to) structures. Maybe this is just an 
inappropriate viewpoint.





-----Original Message-----
From: Richard Fateman
Sent: Sunday, October 06, 2013 5:51 PM

I would expect that if a,b are intervals, that the return value of max(a,b) is either the memory location where a is stored or where b is stored.  Not another location where there is a conversion of a or b to the type of x.  But frankly I don't know what is intended here.