# [XeTeX] fontspec v1.7

Will Robertson will at guerilla.net.au
Thu Jun 23 08:07:19 CEST 2005

Ross Moore wrote:
> how shall we proceed to implement mathematics
> properly ?
>
> Indeed, what does *properly* actually mean now ?

I would suggest that *properly* means that a unicode maths font can be
set up in XeTeX to typeset maths in a maths environment, up to the level
of writing in the literal glyphs if that is desired (but control
sequences in general would be easier).

There are many problems with this, the biggest, as I see it, being that
TeX needs all those extra font dimensions that unicode fonts simply
lack, as far as I am aware. But if I recall correctly, Michael Downes
wrote a package that dealt with maths doing all of the spacing
explicitly, so it's at least possible in theory. (breqn?)

But this is a further reaching goal. The problem started with fontspec
doing bad things with maths, and this is something that needs to be fixed.

First: do we actually want \mathrm to take the font of the text?

If so, then we simply need to remove the Knuthian assumptions that the
maths font can take various accents and analphabetics from the text font
and replace those definitions with fixed references to glyphs in a
similarly old-fashioned font. So, if no other maths fonts are loaded,
then the maths accents should be defined in terms of Computer Modern,
and probably similarly with euler. lucbmath I haven't yet looked through
but I'm sure that situation's similar.

Do we agree so far? For now, maths is strictly legacy, and the maths
font packages need to be patched in XeLaTeX to reflect this. Beyond this
I really don't know enough of the details to comment, yet...

Will