Proportion (∷) symbol in LaTeX

In this tutorial, you will learn how to use the Proportion (∷) symbol in LaTeX. This symbol is known as the “Proportion” notation.

To print this symbol in LaTeX you can use the keyboard key : (colon) two times. Take a look.

\documentclass{article}
\begin{document}

  $$ a : b :: c : d $$

\end{document}

Output:

Also, you can use the \Colon command provided by the stix package. This will give you a slightly different output.

\documentclass{article}
\usepackage{stix}

\begin{document}

 $$ a : b \Colon c : d $$
 $$ a : b :: c : d $$

\end{document}

Output:

Centered Proportion symbol in LaTeX

If you want a vertically centered Proportion symbol in LaTeX then you have to make a \newcommand like,

\newcommand{\dcolon}{\mathrel{\vcenter{\hbox{$::$}}}}

Take a look.

\documentclass{article}
\usepackage{amsmath}

\newcommand{\dcolon}{\mathrel{\vcenter{\hbox{$::$}}}}

\begin{document}

 $$ a : b \dcolon c : d $$
 $$ a : b :: c : d $$

\end{document}

Output: