# How do I put text over symbols?

This is difficult for me to explain, but how do I put words over a symbol? For instance, I want to add words over an equal sign. Anyone know the command/syntax for that?

Also adding ^ doesn't cut it..., I want the text to appear ON TOP.

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What text do you want above the equal sign? –  Gonzalo Medina Sep 25 '12 at 23:55

You can use a combination of \stackrel and \mathclap (from the mathtools package):

\documentclass{article}
\usepackage{mathtools}

\newcommand\myeq{\stackrel{\mathclap{\normalfont\mbox{def}}}{=}}

\begin{document}

\begin{align*}
a &\myeq b \\
&=c \\
&= d.
\end{align*}

\end{document}


If using mathtools is not an option, you can use a \makebox of width 0pt:

\documentclass{article}
\usepackage{amsmath}

\newcommand\myeq{\mathrel{\stackrel{\makebox[0pt]{\mbox{\normalfont\tiny def}}}{=}}}

\begin{document}

\begin{align*}
a &\myeq b \\
&=c \\
&= d.
\end{align*}

\end{document}


Even better, if amsmath has been loaded, is to use \overset instead of \stackrel; a little example using \tiny\sffamily for "def" :

\documentclass{article}
\usepackage{amsmath}

\newcommand\myeq{\mathrel{\overset{\makebox[0pt]{\mbox{\normalfont\tiny\sffamily def}}}{=}}}

\begin{document}

\begin{align*}
a &\myeq b \\
&=c \\
&= d.
\end{align*}

\end{document}


Inside the argument for \mbox one can use some of the font modifiers, as I did in my second and third examples.

Particularly, I don't like this kind of notation (it's not really necessary); you should consider if you really need the text above the equal sign.

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Wouldn't be \mbox better than \text in this case, so that the def is still upshape even e.g. in theorem? –  tohecz Sep 26 '12 at 6:43
@tohecz -- if upshape is always desired, then the expression (as in this case) is probably an operator name, so that approach would be better. –  barbara beeton Sep 26 '12 at 12:44
@tohecz yes; I updated my answer. Thanks you. –  Gonzalo Medina Sep 26 '12 at 14:47
I'd prefer \overset to \stackrel; instead of \mbox I'd use \mathrm or \textnormal. –  egreg Sep 26 '12 at 15:52
@egreg; right; I've added an example with \overset; thank you. I kept the \mbox since I wanted to illustrate changes to the font for the text (which the OP seems to want to apply according to a comment to the other answer). –  Gonzalo Medina Sep 26 '12 at 17:23
$\stackrel{sometext}{=}$


greets

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Is it possible to change the size and fonts of the text? I tried {\small sometext|, but it didn't work. Also the syntax isn't working very well in \begin{align}...\end{align} environment –  jip Sep 25 '12 at 23:36
@jak: Please include a minimal working example (MWE) that shows your current usage and highlight clearly what you want or need changed. Do so via an edit to your post. –  Werner Sep 25 '12 at 23:55
@jak: You can't use \small in mathmode. Have a look at Gonzalo's answer, he successfully uses \tiny there... –  Tom Bombadil Sep 26 '12 at 1:19