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Trying to use the package unicode-math I have been looking for some documentation of \Umathcode, \Umathcodenum, etc. The usually place, the package documentation (http://ctan.org/pkg/unicode-math), does not contain such. Unfortunately, I am not (yet) able to read LaTeX3 source code.

For example, by trial and error it seems that \Umathcode`C="x"yy"zzzz is the right syntax of \Umathcode. Of course, that is different from \mathcode`C="xyzz (at least in the number of bits...).

So how is the syntax of \Umathcode, \Umathcodenum, \Umathchar, \Umathchardef, ...?

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up vote 5 down vote accepted

There is some documentation in xetexref, although you need to be quite familiar with the TeX primitives they replace: http://www.ctan.org/tex-archive/info/xetexref

The xetexref document has a couple of known omissions that I haven't had the chance to fix up, but I think all the maths primitives are (now) in there.

You can also look in the LuaTeX reference documentation, which has analogous primitives with U prefix instead of XeTeX.

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Thx! Yes, at the moment the xetexref documentation is missing some important information, e.g. what is "bit-packed" - "1"4"2460 is not packed to "1042460 but "04202460 - maybe "fields-swapped-bit-packed" ;-). However, the LuaTeX reference contains all the necessary information! (At least a link/reference to the LuaTeX reference in the documentation of xetexref and unicode-math would be helpful.) – e-birk Feb 25 '13 at 15:01

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