初始代码:
\documentclass{book}
\begin{document}
:$\overline {\mathit v}$:
\end{document}
使用unicode 数学包裹:
\documentclass{book}
\usepackage[bold-style=ISO, mathbf=sym]{unicode-math}
\begin{document}
:$\overline {\mathit v}$:
\end{document}
补丁代码:
\documentclass{book}
\usepackage[bold-style=ISO, mathbf=sym]{unicode-math}
\setmathfont{TeX Gyre Termes Math}
\begin{document}
:$\overline {v}$:
:$\overline {\mathit{v}}$:
\end{document}