[Om3] Conditions

[Professor James Davenport]

On Mon, November 3, 2008 1:19 am, David Carlisle wrote:
> couple of quick comments
Thanks - I was afraid I was doing this work in the void.
>> However, it seems to JHD to be purely \luck" that this denes an interval.
>> What about the following?
>
> Not luck, just that the construct is only correct if the specified set
is an interval, MathML doesn't enforce this, any more than it enforces
the fact that the function to be integrated is in fact integrable. This
isn't necessarily a flaw, it might be considered a feature.
Um: I agree completely about integrals, and indeed divide doesn't enforce
that its second argument be non-zero. But 'int' doesn't pretend to be an
assertion about integrability. What THIS use of interval is doing is
asserting intervalness on a set that, a priori, might not be an interval.
It is possibly also contradictory to the spec [4.4.2.4.1]:
"More general domains should be constructed using a domainofapplication
element or one of the other shortcut notations described in Section
4.2.3.2 Operators taking Qualifiers.

The interval element expects two child elements that evaluate to real
numbers."
>> <OMS name="forallrestricted" cd="quantifier2"/>
>
> yes one of the three proposals coming out of the math f2f was to promote
a general cvention that for a binder foo we just had
> an associated binder foowithcondition (either by modifying the name, or
cd, to be decided) to take the condition.
Ah, but that's NOT what I am proposing here: that's a more radical
proposal if (as I understand from definitcond in MK's note) the bound
variables CAN appear in the conditions, which my sectoin 3.3.2 (p. 31)
says  CANNOT make its way into OpenMath as it currently stands.
<OMS name="forallrestricted" cd="quantifier2"/>
has no such problem, since the bound variables do NOT appear explicitly in
the restriction. Text duly tightened up (page 2).

James Davenport
Hebron & Medlock Professor of Information Technology
Formerly RAE Coordinator and Undergraduate Director of Studies, CS Dept
Lecturer on CM30070, 30078, 50209, 50123, 50199
Chairman, Powerful Computing WP, University of Bath
OpenMath Content Dictionary Editor
IMU Committee on Electronic Information and Communication


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