thinkbayes DocBook: emphasis role=math does not yield italics about thinkstats HOT 3 CLOSED

And a related question: is it possible to generate non-italic text inside 
<emphasis role="math">?  I am looking for the equivalent of \mathrm in LaTeX.

From Sanders:

By default, our toolchain does not render <emphasis> with a custom role in 
italics. I've customized this handling so that anything tagged as <emphasis 
role="math"> will now render in italics. 

If you want portions of text inside an <emphasis role="math"> block to be 
non-italic, you can use an <emphasis role="roman"> tag for that, like this:

<emphasis role="math">This text is italic, except for <emphasis 
role="roman">this bit</emphasis></emphasis>

I think this is all you need, but let me know if you see any issues or need 
anything further.

I added a renderer for mathrm in Renderers/DocBook/book.zpts

name: mathrm
<emphasis role="roman" tal:content="self"></emphasis>

And that works.