OK, now I see Re: Motion P1788/M0013.04 - Comparisons - Overflow / Infinity
Ah, yes, now I remember. Even though we are working only
with real numbers, an interval can be bounded or not,
and we can distinguish that with a decoration. However,
a consequence of the fact we interpret [a,Infinity) to
be a set of real numbers is [a,Infinity)*0 = 0. Thus,
the question of the point product Infinity*0 does not
even arise.
Baker
On 9/21/2010 04:25, Arnold Neumaier wrote:
Ian McIntosh wrote:
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AN> We introduced in Motion 8 decorations to be able to distinguish the two
where necessary inninterval bounds by having the decoration IsBounded.
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My only claims are that by distinguishing Overflow from Infinity you can
know whether multiplying whichever by zero gives zero or NaNQ in floating
point, and that if 754 already had that it would be helpful for interval
arithmetic.
See my comment above.
The distiction can already be made with decorations.
We do not need dubious mathematically indeterminate nunbers.
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R. Baker Kearfott, rbk@xxxxxxxxxxxxx (337) 482-5346 (fax)
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Department of Mathematics, University of Louisiana at Lafayette
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