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Re: Linking mfrac-like operators [Re: Linking (chapter 6.4.3) probably underspecified]

From: Michael Kohlhase <m.kohlhase@jacobs-university.de>
Date: Wed, 14 Apr 2010 08:16:03 +0200
Message-ID: <4BC55DA3.1030105@jacobs-university.de>
To: David Carlisle <davidc@nag.co.uk>
CC: "Lange, Christoph" <ch.lange@jacobs-university.de>, "www-math@w3.org" <www-math@w3.org>
Dear David,

I think that Christoph has a point here, we should be able to link the 
"semantic function position" in presentation MathML without changing the 
presentational representation as you are suggesting. Linking what 
appears to be the function e.g. the + in "x+3" or the square root sign 
in $\sqrt{7}$, has applications beyond the ones that Christoph is 
mentioning, e.g. in structural editing. Just that a presentation happens 
to use special layout primitives rather than general ones (like <mo> or 
<mrow>) should not break uniformity of processing and interation.

I do not support Christoph's attempt of solution, but I think we should 
specify what what linking of the general layout schemata would have as 
effects. David's suggestion runs counter all the work we have been doing 
in the elementary math arena, where we tried to inject semantic 
transparency and get rid of fudging mathematical operations with tables ...

I think it would pay off to think about this suggestion some more.


On 13.04.10 18:11, David Carlisle wrote:
> On 13/04/2010 16:55, Christoph LANGE wrote:
>> operators to CD definitions) makes a lot of sense and should be supported.
>> This is now a different topic, therefore I changed the subject.  Maybe not in
>> the way that we define a special behaviour for nested links, but in the way
>> that there is an alternative<mo>-like syntax for such operator
> You could probably get something to work with an munderover using an mo
> with a horizontal stretch line character as the base, which gives you a
> hook to hang the semantics to, You'd then have to either not worry so
> much about the visual spacing or experiment with spacing and phantoms to
> make it look more fraction-like.
> similarly for mroot, you could, I think, put an mroot around an mphantom
> with (unlinked) mphantomed hidden version of your content
> (so the over-bar gets the right size) and then back in a hyperlinked
> version of the operand with some negative spacing.
> But having suggested that in public, I feel compelled to refer you to
> http://www.w3.org/TR/MathML3/chapter3.html#presm.warnfinetuning
> :-)
> David
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  Prof. Dr. Michael Kohlhase,        Office: Research 1, Room 62
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Received on Wednesday, 14 April 2010 06:16:35 UTC

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