# How to keep the paren style of math-font mtpro2?

\documentclass{article}
\usepackage{amsmath, amsfonts, amssymb}%
\usepackage[lite]{mtpro2}

\let\notsimeq\relax
\usepackage{unicode-math}
\setmainfont{XITS}
\setmathfont{XITS Math}

\begin{document}
$A(\lambda) = \PARENS{\begin{matrix} a_{11}(\lambda)&a_{12}(\lambda) & \cdots & a_{1n}(\lambda)\\ a_{21}(\lambda)&a_{22}(\lambda) & \cdots & a_{2n}(\lambda)\\ a_{31}(\lambda)&a_{32}(\lambda) & \cdots & a_{3n}(\lambda)\\ a_{41}(\lambda)&a_{42}(\lambda) & \cdots & a_{4n}(\lambda)\\ \vdots & \vdots &{}& \vdots \\ a_{r1}(\lambda)&a_{r2}(\lambda) & \cdots & a_{rn}(\lambda)\\ a_{s1}(\lambda)&a_{s2}(\lambda) & \cdots & a_{sn}(\lambda)\\ a_{t1}(\lambda)&a_{t2}(\lambda) & \cdots & a_{tn}(\lambda)\\ a_{m1}(\lambda)&a_{m2}(\lambda) & \cdots & a_{mn}(\lambda) \end{matrix}}$
\end{document}


In the following two styles, I prefer the left side. My trouble is that once 'unicode-math' package is set, then I can only get the right side---

• A quick glance of the code seems that \curlybraces has the info about the delimiters. May be it doesn't work because of the engine? In any case try to save the value of \curlybraces after the package is loaded and restore it after begin document? – Manuel Dec 8 '18 at 9:45