Re: What does "infinty as number" mean?
Dan,
If I understand you correctly, your interpretation
(repeated below) is exactly the interpretation is precisely
that used in the definition of csets.
Baker
On 3/2/2009 3:37 AM, Dan Zuras Intervals wrote:
Dear all,
Let me see if I can take a stab at this.
Date: Sun, 01 Mar 2009 18:07:35 -0600
From: Ralph Baker Kearfott<rbk@xxxxxxxxxxxxx> (for Nate Hayes)
To: stds-1788<stds-1788@xxxxxxxxxxxxxxxxx>
Subject: What does "infinty as number" mean?
.
.
.
2. To evaluate the difference (Inf-Inf) or ratio (Inf/Inf) of two
infinities, the infinities are replaced with a real number x and
then the arithmetic operation is considered in the limit as the
magnitude x tends towards infinity. The same is true for 0*Inf,
which leads to 0*Inf=0.
I disagree with this interpretation& the interpretation
that falls out naturally from 754 involving NaNs.
I feel the proper interpretation of inf OP inf should be
lim inf x OP y as x& y approach the desired
infinity INDEPENDENTLY
if the result is to appear as a lower bound&
lim sup x OP y as x& y approach the desired
infinity INDEPENDENTLY
if the result is to appear as an upper bound.
No other interpretation gives strict containment of the
associated real expression.
.
.
.
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R. Baker Kearfott, rbk@xxxxxxxxxxxxx (337) 482-5346 (fax)
(337) 482-5270 (work) (337) 993-1827 (home)
URL: http://interval.louisiana.edu/kearfott.html
Department of Mathematics, University of Louisiana at Lafayette
(Room 217 Maxim D. Doucet Hall, 1403 Johnston Street)
Box 4-1010, Lafayette, LA 70504-1010, USA
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