答案1
我会避免使用\overline
: ,\bar
因为它更优雅。如果你真的认为它太短,你可以尝试\widebar
(参见https://tex.stackexchange.com/a/391193/4427)
\documentclass{article}
\usepackage{amsmath,amssymb}
% for \widebar
\DeclareFontFamily{U}{mathx}{}
\DeclareFontShape{U}{mathx}{m}{n}{ <-> mathx10 }{}
\DeclareSymbolFont{mathx}{U}{mathx}{m}{n}
\DeclareFontSubstitution{U}{mathx}{m}{n}
\DeclareMathAccent{\widebar}{\mathalpha}{mathx}{"73}
% fixed overline
\newcommand{\foverline}[1]{\smash[t]{\overline{#1}}\vphantom{#1}}
\begin{document}
Bar: $X^D+\bar{X}^D$
Widebar: $X^D+\widebar{X}^D$
Overline: $X^D+\foverline{X}^D$
\end{document}