# Symbol for “corresponds to” (equals sign with hat) [duplicate]

Recently in some LaTeX documentation I noticed that there is a special LaTeX command for the symbol meaning "corresponds to", which is similar to an equal sign with a hat on top. \hat{=} or \widehat{=} both do not give satisfying results (my personal view). Unfortunately, I cannot remember which documentation it was! Does anyone know the command or the documentation where to find it?

The symbol I am looking for:

PS: I have already tried detexify but it didn't produce anything useful! Also, browsing the comprehensive LaTeX symbol list wasn't successful.

-

## marked as duplicate by Joseph Wright♦Jun 27 at 17:09

$\cong$ might be what you want. Other related symbols are \simeq, \sim, \approx. There is a symbol bible out on the web called symbols-A4.pdf. Very useful. –  Steven B. Segletes Mar 20 '13 at 12:21
In addition to trying the above, could you perhaps draw what you want and upload it here? (Carefully drawing it on paper and then taking a picture is probably the easiest way.) Mathematical notation varies greatly from region to region; e.g. my training urges me to use something similar to \func. –  Sean Allred Mar 20 '13 at 12:25
\stackrel{\frown}{=} –  hpesoj626 Mar 20 '13 at 12:26
Since you even linked to the Comprehensive LaTeX symbol list: Table 76, second column, last row on page 32 ;-) –  mafp Mar 20 '13 at 12:32
I addition to @mafp's command \mathrel{\widehat{=}} might help you. It would help us, if you discribe, what is not good with the commands you found. –  Dominikus K. Mar 20 '13 at 12:35

Try this. Of course, the parameters can be adjusted to change vertical separation height or horizontal width of wedge relative to = sign, or aspect ratio of wedge. Note that the appearance of this is not quite the same as \hateq cited in comments above, but better conforms to the symbol illustrated by the questioner.

\documentclass{article}
\usepackage{scalerel,amssymb}

\newcommand\equalhat{%
\let\savearraystretch\arraystretch
\renewcommand\arraystretch{0.3}
\begin{array}{c}
\stretchto{
\scalerel*[\widthof{=}]{\wedge}
{\rule{1ex}{3ex}}%
}{0.5ex}\\
=%
\end{array}
\let\arraystretch\savearraystretch
}

\begin{document}

$x^2 \equalhat \begin{array}{c}a\\b\\c\end{array}$

\end{document}


-