Math upright Latin and Greek styles

[Hans Åberg]

> On 16 May 2016, at 18:56, Philippe Verdy <verdy_p at wanadoo.fr> wrote:
> 
> I do not advocate changing that, but these legacy *TeX variants have their own builtin sets of supported fonts with their implicit style and use them with the normal letters, just like what is done in HTML when you apply an italic style. Has these *TeX variants exist this way they don't need these additions that will be needed only on newer *TeX variants that will not use explicit font variants in their encoding, but directly new distinguished code points (without explicit font style tagging).

The ConTeXt macro package default engine is LuaTeX, which uses UTF-8 for text files and UTF-32 internally, and combines the effort of several of those other, older versions. Then one can use the STIX fonts (or XITS) which are Unicode.