Re: "natural interval extension"
John (et al),
I think you make a good point. Why continue a usage if it isn't
precise? Although we're not talking about a normative part
of the standard, this is related to the question of whether
a standard should strictly codify existing practice or seek
to standardize something new that improves on existing practice.
Taking John's points into account makes Ned's proposal to simply
add his proposed explanatory paragraph more attractive to me.
(He could also perhaps add that the definition in the standard is
unambiguous, and is a property of the real-valued function.)
Best regards,
Baker
On 12/08/2015 06:25 AM, John Pryce wrote:
.
.
.
A.If one thinks of "interval extension" as being a property of a *function*,
I maintain that the definition in 1788 is the most "natural".
B.If one thinks of it as being a property of an *expression*, then the one
that's "common in the literature" is sort of natural. Or it would be, if
the books/articles making the definition made clear that many different
expressions can define the same function. But they don't. Even Warwick
Tucker's book, which I find exemplary in most ways, is vague, as Michel
Hack pointed out on 7 Dec. (WT promised me to make it clearer in a future
edition.)
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Ralph Baker Kearfott, rbk@xxxxxxxxxxxxx (337) 482-5346 (fax)
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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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