Russian characters in equations without \textup in XeLaTeX

Question

I want to change LaTeX engine from PdfLaTeX to XeLaTeX. There are a lot of formulas and equations with Russian text inside. And it used without any commands.

MWE for pdflatex:

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage[russian]{babel}
\usepackage{mathtext} 
\usepackage[T2A]{fontenc} 

\begin{document}

    Формула: $F_{подпись} = Ф$

    Уравнение:
    \begin{equation}
    X_{первый} = Y_{второй}
    \end{equation}

\end{document}

I tried the same example with XeLaTeX. There is no errors, but Russian characters are displayed only with \textup command, like it was said in this answer:Cyrillic symbols in math equation xetex

\documentclass{article}
\usepackage{unicode-math}
\usepackage{polyglossia}  
\setdefaultlanguage{russian}  
\setmainfont{Liberation Serif} 
\setmathfont{Asana Math}

\begin{document}

    Формула: $F_{подпись} = Ф$

    Уравнение:
    \begin{equation}
    X_{первый} = Y_{\textup{второй}}
    \end{equation}

\end{document}

Are there any ways to do it without \textup?

I'm assuming первый is a named index, in which case is always should be typeset in the upright text font so it is not confused with п*е*р*в*ы*й or six separate indices. — daleif, Dec 19 '18 at 14:19
@daleif Yes, it is index, but it should be written like a whole word. — Shalom Alecheim, Dec 19 '18 at 14:26
Does https://tex.stackexchange.com/questions/201239/cant-get-unicode-symbols-in-math-mode solve your problem? — JPi, Dec 19 '18 at 14:44
Which is why you mark it with textup, whole word in the upright text font. We have to do the same in Latin based scripts — daleif, Dec 19 '18 at 15:29
@daleif It was just an example, which shows that Russain text in math mode is not displayed without \textup, but displayed with it. — Shalom Alecheim, Dec 19 '18 at 15:35

Russian characters in equations without \textup in XeLaTeX

0 Answers0