From: David Carlisle <davidc@nag.co.uk>

Date: Tue, 4 Apr 2006 15:54:51 +0100

Message-Id: <200604041454.k34Esp03005415@edinburgh.nag.co.uk>

To: juanrgonzaleza@canonicalscience.com

CC: www-math@w3.org

Date: Tue, 4 Apr 2006 15:54:51 +0100

Message-Id: <200604041454.k34Esp03005415@edinburgh.nag.co.uk>

To: juanrgonzaleza@canonicalscience.com

CC: www-math@w3.org

> The basis for over and under scripts in your example is incorrect. I didn't reply to your over under question as I had no idea what you meant by the ascii art Over sup Base sub under I would have guessed that you meant an over-under construction with base having a sub and superscript, in which case the MathML that you said that you recieved is correct. If you mean that you want the over and under to be positioned over the Base without being affected by the presence of the sub and sub then a) why? and b) what possible markup would you suggest that could do that (You can't do it in TeX either). > The question is that MathML designers have done a couple of errors in the > specification. This is a clear example. It's not clear at all. As your example is just 5 words and some white space, we have to guess what mathematical relationships you mean before anyone can suggest any markup. >. In mathematical SGML, "mathematical SGML" is far more general than you mean. XML is a profile of SGML and as such MathML is a mathematical SGML dtd (and has been processed with core SGML tools such as nsgml and the jade dsssl engine). You presumably have some other DTD in mind, perhaps you should say how your example would be encoded in that dtd. > Those abnormal MathML code is being generated by tools are listed in the > w3c official site for MathML. and your point is? Yesterday I was sent a message in german, I passed it through google's german to english translator. the "english" that resulted was a little "strange" but that doesn't mean that I should deduce that because structural differences between german and english make translation non trivial that there is an error in the design of either language. > <msup><msub>basis sub</msub>sup</msup> > > IS DIFERENT. The basis for the superscript in above MathML is incorrectly > encoded. and MathML folks saw obligated to introduce a new tag and a new > parsing model (now with three arguments) > > <msubsup> basis sub sup</msubsup> You need both of those concepts whatever the markup you use. Mathml encodes them the way you show, in TeX the first is {a_b}^c and the second is a_b^c > If you want encode some other kind of sub or superscripts for example > prescripts one, then above model is not good again and MathML needs > introduce new <multiscript>, <prescript/> and <none/> tags and a new > processing model. More complexity. on the contrary multiscripts and prescripts are one place where mathml markup (and underlying layout model) is vastly superior to teX's. TeX has no model of prescripts at all, and none of multiscripts other than a single sub-super pair. To do pre-scripts or multi-scripts in TeX you have to do a lot of explict spacing. It's possible to write macros that try to do the spacing automatically but it's not easy. Have a look at the multiscript code in amslatex, it's horrendously complicated. > In SGML math, the model for scripts is more > powerful being more simple, just four basic tags for under, over, sub, and > sup are combined with <subform> Ah so by SGML you mean ISO 12083 So how would you mark up you first example in ISO 12083 ? David ________________________________________________________________________ This e-mail has been scanned for all viruses by Star. The service is powered by MessageLabs. For more information on a proactive anti-virus service working around the clock, around the globe, visit: http://www.star.net.uk ________________________________________________________________________Received on Tuesday, 4 April 2006 15:03:45 UTC

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