Re: [possible patch] Basic fontspec code for LuaLaTeX and XelaTeX (was "LaTeX export: when is it more useful...")

[Max Nikulin]

On 11/07/2022 21:23, Juan Manuel Macías wrote:
> Max Nikulin writes:
>
> \ifpdftex, \ifPDFTeX
> True if PDFTEX is in use (whether writing PDF or DVI), so this is true
> for documents processed with both the latex and pdflatex commands.
>
> So the code says: if pdfTeX is used, do nothing; else, add this (luatex
> and xetex related) code.

Likely it is not relevant to Org, but for the following document

\documentclass{article}
\usepackage{ifpdf}
\begin{document}
\ifpdf PDF\else Not PDF\fi
\end{document}

I get "PDF" when I use pdflatex and "Not PDF" when I run latex.

> Yes, that is true, sorry. I don't work with math. But:
>
> \setmathrm{⟨font name⟩}
> \setmathsf{⟨font name⟩}
> \setmathtt{⟨font name⟩}
> \setboldmathrm{⟨font name⟩}
>
> Now, weren't we talking about ensuring a minimum readability out of the
> box in case non-Latin characters are used?

Mathematical expressions may contain non-latin characters as well. 
\text{} may be a rescue (anyway such expression usually appears poorly 
formatted), but if I remember correctly, it is better to use math mode 
commands to get accurate spaces in accordance to TeX design. So math 
fonts with wider coverage is somewhere close to minimum readability.