# What is the latex code for the symbol “two colons and equals sign”? [duplicate]

I wish to use the symbol as in the following picture, however, I can not find it. Can someone help me?

-

## marked as duplicate by Ian Thompson, doncherry, Werner, Claudio Fiandrino, HerbertJun 27 '13 at 14:33

What have you tried for finding the symbol (so people don't have to duplicate your efforts)? – Jake Jun 27 '13 at 13:31
In particular, you should look at tex.stackexchange.com/q/14/86 and see if you can find it using one of the methods there. If you can't, you should say so in the question. – Loop Space Jun 27 '13 at 13:32
I use this tool detexify.kirelabs.org/classify.html, and also I have tried to find in some documents which map the symbols to latex code. Thanks. – sweetyBaby Jun 27 '13 at 13:33
@AndrewStacey I have tried, thanks. – sweetyBaby Jun 27 '13 at 13:34
@AndrewStacey Don't think this is in the Detexify database (doesn't seem to cover the necessary packages) – Joseph Wright Jun 27 '13 at 14:09

The symbols is called \Coloneqq in the package txfonts/pxfonts. Here is the rest of the symbols:

-

mathtools package has these symbols with the following argument

The font packages txfonts and pxfonts provides various symbols that include a verti cally centered colon but with tighter spacing. For example, the combination := exists as the symbol \coloneqq which typesets as <tighter symbol picture> instead of <larger symbol picture>. The primary disadvantage of using these fonts are the support packages’ lack of support for amsmath (and thus mathtools) and worse yet, the side-bearings are way too tight; see [4] for examples. If you’re not using these fonts, mathtools provides the symbols for you.

Here is a sample

\documentclass{article}
\usepackage{mathtools}

\begin{document}

$\coloneqq \Coloneqq \coloneq \Coloneqq \eqqcolon \Eqqcolon \eqcolon \Eqcolon \colonapprox \Colonapprox \colonsim \Colonsim \dblcolon$
\end{document}


-
newtx and newpx replace txfonts and pxfonts (respectively), with far better metrics (inc. sidebearings). doesn't help with the interaction with amsmath, though, afaik – wasteofspace Jun 27 '13 at 16:11