I am using \boxed to draw a small box around a symbol in math mode. I would, however, like to decrease the padding between the symbol and the box. While I found solutions involving other commands/packages, I'd prefer to stuck to stick to \boxed. Also, adding \smash does not work.

MWE:

\documentclass{article}
\begin{document}

$\boxed{\leq} \quad \boxed{\smash{\leq}}$

\end{document}


\boxed in amsmath is defined using a regular \fbox:

\newcommand{\boxed}[1]{\fbox{\m@th$\displaystyle#1$}}


So, setting \fboxsep would modify the gap. Here is an example:

\documentclass{article}
\usepackage{amsmath}% http://ctan.org/pkg/amsmath
\begin{document}

$\boxed{\leq} \quad \setlength{\fboxsep}{.5\fboxsep}\boxed{\leq} \quad \setlength{\fboxsep}{.5\fboxsep}\boxed{\leq} \quad \setlength{\fboxsep}{.5\fboxsep}\boxed{\leq}$

\end{document}


In that sense it's possible to redefine \boxed to take an optional argument that sets the width:

\makeatletter
\renewcommand{\boxed}[2][\fboxsep]{{%
\setlength{\fboxsep}{#1}\fbox{\m@th$\displaystyle#2$}}}
\makeatother


This allows one to use, for example, \boxed[-\fboxrule]{\leq} to see the bounding box around \leq.

• But your first example above seems to make the change to \boxed somewhat permanent, i.e. if I later use another plain \boxed without changes to \fboxsep, the padding is still decreased. How would I make the one-shot padding-decreased smaller box without affecting future ones? - Other than that, the solution works perfectly, thanks! – Bernd Jul 17 '13 at 12:45
• @Bernd: I've added an example of how to update \boxed to take an optional argument which does a local change to \fboxsep. However, if you wish to do this manually, surround the \setlength...\boxed.. with braces: {\setlength...\boxed..}. That defines the scope for the change. – Werner Jul 17 '13 at 12:47
• Ah, the braces did the trick. Still know so little about how the LaTeX syntax works. Thanks! – Bernd Jul 17 '13 at 12:49