- From: David Carlisle <davidc@nag.co.uk>
- Date: Wed, 8 Dec 2004 17:12:22 GMT
- To: wconstan@insightful.com
- CC: www-math@w3.org

> Questions: Will MathML facilitate complicated equations as does LaTeX? > Is it conceivable that LaTeX equations may be entered within > special MathML tag(s) so that conversion is done "behind the scenes"? As others have said, basically the answers to both those questions are yes. In addition to authoring in latex and converting to MathML, you also have the option of authoring in MathML and converting to latex. LaTeX is definitely easier to author than MathML if you are just using a text editor (although authoring MathML just in emacs isn't so bad: we do a fair amount of that here:-) however there are other options, eg several commercial or free projects to produce more or less wysiwyg MathML editing, or saving MathML from systems such as Mathematica or maple. Even if authoring in MathML just in a text editor, the benefits that you gain over going in the other direction are much tighter control over the input (latex doesn't really have much of a notion of validation) and an easier conversion route. It's definitely easier to convert MathML to latex than to go in the other direction, as the input is far more structured. Which direction latex->MathML or MathML->latex is better depends on several things, not least personal preference, so there isn't a simple recommendation that can be given. As far as expressivity for complicated expressions goes, MathML has essentially enough constructs to lay out mathematics as well as TeX. Whether a particular renderer lays them out well is of course a feature of that renderer; unlike TeX which is only designed to work with one layout engine. the only MathML renderer that I'm prepared to comment on in public is the one I implemented in pmathmlcss.xsl available from the W3C site, which uses CSS and javascript to display MathML in a web browser, the typographic quality there is considerably worse than that of TeX, but as it's only intended as a last fallback if nothing else is available... The main difficulty is multi line displayed mathematics, the problem here is not so much a difference between the languages, so much as the way they are used: The TeXbook says of this: It's quite an art to decide how to break long displayed formulas into several lines; TeX never attempts to break them, because no set of ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ rules is really adequate. The author of a mathematical manuscript is generally the best judge of what to do, since break positions depend on subtle factors of mathematical exposition. For example, it is often desirable to emphasize some of the symmetry or other structure that underlies a formula, and such things require a solid understanding of exactly what is going on in that formula. So in TeX all line breaking is manual, and in LaTeX we have the many different flavour of alignment possibilities given by the amsmath package for example. MathML probably has enough alignment primitives to mimic that (although not all systems currently support malign in its full form, you can get a long way just with mtable) however in many cases you _don't_ want to do this. In TeX it is reasonable for the author to have full control as the document is targeted at a particular page size, set of fonts, etc, but in MathML, while one could use MathML to target a particular document renderer the mindset is that you should be writing a multi use document that still works, even if the reader resizes the window, or choses a larger font set (or is using an audio renderer). This means that when converting from LaTeX you have to make a choice of trying to preserve your carefully tuned manual breaks in the MathML or whether to lose them and live with the possibly less optimal breaks produced by the formatter, both of those choices are possible but deciding which one to take isn't always easy. Especially if (as often happens) the LaTeX markup isn't sufficiently clean that you can easily tell if the multi-line display really does logically need to be on several lines (eg a set of simultaneous equations) or whether it is really just a long equation broken so that it fits a particular page size. 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 Wednesday, 8 December 2004 17:12:50 UTC