Importing accents and wide accents

I know how to import a single symbol from a different font (Importing single symbol from MnSymbol), but it is possible to import an accent?

For example, I would like import \underbrace and \widetilde from \usepackage{mathabx}

• In general it is a bad idea to replace parts of your fonts as they were designed to be coherent. The idea of loading symbols from another math font is thought for amending symbols that are missing. An example would be upright lowercase Greek letters, which are not part of Computer Modern. Nov 10, 2015 at 17:29
• Relevant to wide tilde: tex.stackexchange.com/questions/63545/big-tilde-in-math-mode Nov 10, 2015 at 17:31

I copied the relevant definitions from mathabx.sty and mathabx.dcl.

\documentclass{article}
\makeatletter
\DeclareFontFamily{U}{mathx}{\hyphenchar\font45}
\DeclareFontShape{U}{mathx}{m}{n}{
<5> <6> <7> <8> <9> <10>
<10.95> <12> <14.4> <17.28> <20.74> <24.88>
mathx10
}{}
\DeclareSymbolFont{mathx}{U}{mathx}{m}{n}

%%%%%%%%%
% Tilde %
%%%%%%%%%
\DeclareMathAccent{\widetilde}{0}{mathx}{"72}

%%%%%%%%%%
% Braces %
%%%%%%%%%%
\DeclareMathSymbol{\braceld}{0}{mathx}{"68}
\DeclareMathSymbol{\bracemd}{0}{mathx}{"69}
\DeclareMathSymbol{\bracerd}{0}{mathx}{"6A}
\DeclareMathSymbol{\bracexd}{0}{mathx}{"6B}
\DeclareMathSymbol{\bracelu}{0}{mathx}{"6C}
\DeclareMathSymbol{\bracemu}{0}{mathx}{"6D}
\DeclareMathSymbol{\braceru}{0}{mathx}{"6E}
\DeclareMathSymbol{\bracexu}{0}{mathx}{"6F}

\def\braceexwd{2mu}
\def\bracevkern{0pt}

\def\bracefill#1#2#3#4{$\m@th #1#4\mkern-\braceexwd \cleaders\hbox{$#4$}\hfill \mkern-\braceexwd#4#2#4\mkern-\braceexwd \cleaders\hbox{$#4$}\hfill \mkern-\braceexwd#4#3$}

\def\overbrace@#1#2{\mathop{\vbox{\m@th\ialign{##\crcr
\noalign{\kern\bracevkern}
#1\crcr\noalign{\kern\bracevkern\nointerlineskip}
$\hfil\displaystyle{#2}\hfil$\crcr}}}\limits}

\def\underbrace@#1#2{\mathop{\vtop{\m@th\ialign{##\crcr
$\hfil\displaystyle{#2}\hfil$\crcr
\noalign{\kern\bracevkern\nointerlineskip}
#1\crcr\noalign{\kern\bracevkern}}}}\limits}

\def\overbrace{\overbrace@{\bracefill\braceld\bracemd\bracerd\bracexd}}
\def\underbrace{\underbrace@{\bracefill\bracelu\bracemu\braceru\bracexu}}
\makeatother
\begin{document}
$\underbrace{\widetilde{a+b+c}}$
\end{document}


• Thank you for your answer, so it should only import symbols? Nov 10, 2015 at 20:09