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Re: comments re draft version 2.0

From: David Eppstein <eppstein@ics.uci.edu>
Date: Mon, 10 Apr 2000 23:00:09 -0700
To: www-math@w3.org
cc: jsdevitt@radicalflow.com
Message-ID: <5546313.3164396409@cx344290-c.irvn1.occa.home.com>
On 4/11/2000 12:32 AM -0400, Stan Devitt wrote:
> One of the purposes of this review is to gauge how the needs of the
> target user community are being met and comments such as yours help
> immensely.

Thanks...

> Of the examples you have raised, I suspect there may be pretty wide
> support for direct support of BigOh, LittleOh,  floor and  ceiling while
> the others may infrequent enough to be  handled by the extension
> mechanism.

In undergraduate teaching I use all five of O/o/Omega/omega/Theta (O by 
far most often, the others roughly equally), so my preference would be to 
treat them all equally.  In more researchy writing I think I use Omega 
second-most frequently after O. But adding the ones you list would 
certainly help.

> Thoughts?  Are there any other ommissions that
> stand out for you?

It does seem a little odd (if your target really is K-13 math) that 
section 4.4 doesn't have a subsection for basic geometric notations such 
as angles, line segments, triangles, arcs, chords, measures of angles, 
parallel, perpendicular, etc., as might be found in a high school geometry 
class.

In elementary number theory, it might be appropriate to have a relation 
"divides" or "is a factor of" (vertical bar).  Would one also have a 
relation "doesn't divide" (slashed vertical bar) or does the <not/> take 
care of that?  I notice that some relations (e.g. the set ones) have 
slashed negations included while others (equivalent) don't.

On a related note, the default rendering of notsubset is shown as a 
slashed prsubset, and the default rendering of notprsubset is shown as a 
slashed subset.  Is this backwards, or am I confused?  Shouldn't the 
default rendering of xor be a circled plus instead of the word "xor"?  And 
a set-theoretic symmetric-difference function would help avoid the 
temptation to misuse xor for that purpose, but maybe it's sufficient to 
use <xor definitionURL=...>?

Other than that, if I find anything, I'll let you know of course, but it's 
hard to see what's missing or awkward just by scanning the spec -- it 
really takes trying to translate many whole documents from many sources 
into the new system, and I don't have the time or motivation to do much of 
that.
-- 
David Eppstein       UC Irvine Dept. of Information & Computer Science
eppstein@ics.uci.edu http://www.ics.uci.edu/~eppstein/
Received on Tuesday, 11 April 2000 02:00:17 GMT

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