# Problem in using amsmath and mathastext packages

I am trying to use Arial fonts and fira-math fonts and compiling with lualatex. I am also using mathastext. However there is a problem. The \begin{bmatrix}\end{bmatrix} doesn't work. Here is a MWE, compiled with lualatex.

\documentclass{article}
\usepackage{firamath-otf}
\setmainfont{Arial}[Scale=1.2]
\usepackage{amsmath}
\usepackage{mathastext}
\begin{document}
This is running text.
$\cos 2\theta=2\cos^2\theta-1$
$\begin{bmatrix} a&b&2\\ A&b&1\\ c&X&Z \end{bmatrix}$
\end{document}

Is there a work around for this? I want to use fira-math so, loading fontspec with no-math option is not possible I think.

• firamath-otf loads the unicode-math package. You shouldn't use this together with mathastext. – Ulrike Fischer Mar 25 at 13:30

I use something like this. You can download Fira Math font from GitHub or use firamath-otf, of course. My advice is not to use text fonts as math fonts; they are missing a number of font dimens and glyphs needed for good math. So using them for math is always only a work-around.

\documentclass{article}
\usepackage{amsmath}
\usepackage[mathrm=sym]{unicode-math}
\setmathfont{Fira Math}
\setmainfont{Arial}%[Scale=1.2] too large ..

\begin{document}
This is running text.
$\int_0^{\mathrm{\pi}} \sin x \, \mathrm{d}x = 2$
$\cos 2\theta=2\cos^2\theta-1$
$\begin{bmatrix} a & b & 2 \\ A & b & 1 \\ c & X & Z \end{bmatrix}$
\end{document}

• Thanks. Unfortunately, using text fonts for Mathematics is not my choice. It is forced upon me. I am now using arial for mathematics text in pdflatex with the help of several crude hacks. I was wondering if it will be any easier in lualatex or xetex. I will try out your solution instead of using mathastext.. – S. Venkataraman Mar 29 at 13:04