[XeTeX] LM math and map files

[Mojca Miklavec]

Hello,

Can someone please explain me if/when/why the map files (for math) are
needed in XeTeX?

After begging for LM map files for XeTeX, I figured out (if not
mistaken) that xelatex never tries lo load lm-math.map, and math still
works OK.

ConTeXt loads lm-math.map and lm-rm.map exlicitely, and if they're not
present for dvipdfm, the documents are broken. Now I removed explicit
loading of lm-math.map and tried the same for iwona-mi.map,
iwona-sy.map, ... and some simple math seems to work OK. (I wanted to
test how iwona math works with xelatex, but I didn't know how to do
that.) Now I'm completely confused ... Was the math I was testing with
too simple, did I forget to remove some traces of those map files, or
did I misunderstand the concept completely?

I would be glad to hear any explanation about it, so that the issue
can be fixed properly either in ConTeXt or in those famous Polish
fonts (iwona, kurier, antykwa, lm).

Thanks a lot,
    Mojca