Epub Revision - mathematics support

[Nate the great]

No native support for mathematics. The lack of a native schema to represent mathematical equations (MathML) limits applicability and interoperability of eBook in the textbook and academic publishing segments.

I'm running out of new ways to invite comment.

[alecE]

I'm certainly not expert on the technicalities of the epub standard, but support for maths equations is definitely required - I'm suffering through a book with just a few equations, which (on my Sony 550 at least) show in smaller type, in a delicate shade of unreadable light grey, and cannot be enlarged to a legible size. OK, end of rant; yes, mathematical equation support required. :-)

[DawnFalcon]

...MathML requirement.

Really, it's not that hard to figure out the solution.

[pholling]

What THEY said
I want to at the least be able to present equations legibly, and hopefully plug in some values. Quizzing for technical subjects is more about choosing the right set of equations than being diligent enough to not screw up the answer.

[frabjous]

Yeah, just including MathML in the spec seems like the no brainer solution.

I am curious though what it mean with regard to math font support. Would it then be required that any ePub device come with a full stock of symbol fonts? Perhaps the STIX fonts, or any font set with the same range of coverage. How feasible is this? I don't really have a good sense of this.

[HarryT]

An equation is simply a graphic. Can this not be done with SVG?

[pdurrant]

Having just done a little [more] research to refresh my memory of TeX, and to find out a little about MathML, it's a no-brainer.

The next ePub specification needs to include [presentation] MathML as a required component. I'm not entirely sure without looking into it more deeply than I want to, whether content MathML is needed.

http://www.mathmlcentral.com/history.html is a fairly succinct summary (granted, from what might be a biased source). There seems to be plenty of work going on on ways to get TeX quality typesetting from MathML expressions, and the ability to copy/paste from MathML to ctual methematical evaluation software seems an important ability that any purely layout based system (i.e. TeX) can never match.

It is possible to typeset equations using an SVG graphic, but these are awkward to create, and only a little better than a bitmap version.

[WillAdams]

HarryT, an equation is a bit more complicated than a graphic --- it's a serial description of a complex statement which is spread out along two axes. Granted, one could brute force this by doing all equations as SVG but then:

- they wouldn't be breakable / re-flowable
- they wouldn't be readable (by screen readers / TTS)
- they wouldn't be guaranteed to line up nicely on the baseline if the text size was changed
- they wouldn't be editable as equations

What was the point of developing MathML if it's not to be used in such situations?

William

[HarryT]

Originally Posted by WillAdams

What was the point of developing MathML if it's not to be used in such situations?

William

I was just asking whether SVG couldn't fulful the same requirements. From what you've said, it clearly can't (I hadn't considered such things as screenreaders). Thank you for your lucid explanation.

[Nate the great]

Originally Posted by HarryT

An equation is simply a graphic. Can this not be done with SVG?

You could also put the text of a book in a graphic. Do you think that's a good idea?

The thing is, equations have been put in images not because it was a good idea, but because that was the only way to do them. The alternative was to not have them at all.

[HarryT]

Originally Posted by Nate the great

You could also put the text of a book in a graphic. Do you think that's a good idea?

Occasionally, yes. If you just want a small snippet of text that's in a different character set, and you don't know whether or not all your target readers will be able to display it, then using a graphic can be a good solution.

[pdurrant]

Originally Posted by HarryT

Occasionally, yes. If you just want a small snippet of text that's in a different character set, and you don't know whether or not all your target readers will be able to display it, then using a graphic can be a good solution.

But with ePub a much better solution is to embed a small subset of the font in question and format the text with that..... until Apple went and created an ePub reader that doesn't support embedded fonts!

I really hope they fix that soon.

[HarryT]

OK, let's suppose that MathML is adopted as a part of the ePub standard. What will happen with all the ePub devices which don't support it? Is it possible to say "if the device supports MathML, display the equation properly; if not, display this SVG image" or something of the sort?

[frabjous]

But with ePub a much better solution is to embed a small subset of the font in question and format the text with that..... until Apple went and created an ePub reader that doesn't support embedded fonts!

Yeah, it's completely ridiculous. With font embedding, you can do a decent job formatting most equations just with HTML and CSS and the right symbols. Of course, MathML would make it much easier, but it still uses symbols that come from a font. MathML support without font embedding support (or a requirement that certain symbol fonts be available) would be worthless.

Even SVGs often have text components (and SVGs used for equations, whether converted from MathML or not, pretty much always do), and the font still needs to be available to display the SVG correctly.

The iPad just pisses me off in so many ways. Oh no, if we let people use custom fonts in their documents it might offend Steve Jobs's aesthetic sensibilities. Far better that we keep people unable to read mathematical texts; after all, math might lead to engineering, and engineering might lead to noticing that the darn iPad can't be opened.... sigh...

[Jellby]

Originally Posted by HarryT

OK, let's suppose that MathML is adopted as a part of the ePub standard. What will happen with all the ePub devices which don't support it? Is it possible to say "if the device supports MathML, display the equation properly; if not, display this SVG image" or something of the sort?

Yes, that could be done with "fallbacks", which are already a feature of the current spec (if the reader supports this feature, use this content, if it doesn't, use this other "support-is-required-by-the-spec" content instead).

If MathML is addopted as a required feature of the next standard (say ePUB-2), then some readers will be ePUB-2 compliant, some readers will be only ePUB, some books will only work fine with ePUB-2 (if they include MathML content with no fallback), some will work with ePUB or ePUB-2 (if they don't have MathML, or if they include proper fallback). Current ePUB readers will continue reading ePUB books, future ePUB-2 readers will be able to read both ePUB and ePUB-2 books. In the worst case, it won't be much worse than the current situation with SVG, fonts, etc.