[lucida] Problems with Lucida OT font typesetting

[Bruno Voisin]

> On 2 May 2022, at 05:06, John H Lienhard <lienhard at mit.edu> wrote:
> 
> BTW, the bm package is aimed at LaTeX, and not really compatible with unicode-math.

David Carlisle (the author of bm) developed an extended version for OpenType fonts, called bmx. It worked fine with XeTeX (I used it for several years), but was only partially functional for LuaTeX and has been shelved for some time. It's at

	https://github.com/davidcarlisle/dpctex/tree/main/bm

Five years ago, at

	https://github.com/wspr/unicode-math/issues/409#issuecomment-334495565

David wrote

"I have somewhere a version of bm that works with classic fonts with luatex
(that is just avoids the "interesting" syntax changes in `\mathcode`
handling required)
but doing anything for opentype fonts and unicode-math is a bit tricky as
\symbf covers most use cases and \mathbf covers some more and for the other
things that users might hope \bm to do something it will fail as there is
no matching bold math font, so it's parked for a while: other priorities:-)"

At that time, unicode-math wasn't as flexible; now, it seems to do most of what bm did. One important thing is to preserve the mathematical class, so that spacing around the bold character is kept consistent. For example, it used to be that if you defined a bold version of the dot product operator with unicode-math, you needed to use something like \mathbin{\symbf{\cdot}}; now I think that \symbf{\cdot} works just as well.

Bruno Voisin