# How can I use \not with more than one symbol?

When using \not in math mode only the following symbol gets crossed, is there any way to apply it to more than one symbol evenly as if it were one operator?

I tried \not{<:} but it doesn't work.

• Related/duplicate: How to negate a specific symbol? – Werner Jan 19 '17 at 18:43
• \not is just symbol, its bounding box has zero width and the symbol is actually to the right of that box by an amount designed to place in top of many following symbols. – Andrew Swann Jan 19 '17 at 20:21

You can use \mathclap from mathtools:

\documentclass{article}
\usepackage{amsmath}
\usepackage{mathtools}

\DeclareMathOperator{\lecolon}{<:}

\begin{document}
$\not\mathclap\lecolon$
%your whole expression should be something like
$\gamma\not\mathclap\lecolon\mkern10mu\tau$
\end{document}


Anyways, I think your expression looks more like the \not reffers only to the less sign and it's followed by a colon:

$\gamma\not\mathclap<:\tau$


which can finally be slightly refined to

$\gamma\mkern-2mu\not\mkern2mu\mathclap<:\tau$


• Note, of course, that the \mathclap totally kills the width of its contents, so if you're using \not\mathclap\iff or some other longer symbol then you'll need to adjust your \mkerns. (Also, you should consider using mathtools's <\vcentcolon instead of <: .) – wchargin Jan 19 '17 at 23:01

Here my MWE. What do you prefer?

\documentclass[a4paper]{article}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\usepackage[english]{babel}
\usepackage[utf8x]{inputenc}
\usepackage[T1]{fontenc}
%%%%%%%%%%%%%%%%%%%%%%%%Useful packages
\usepackage{amsmath}
\usepackage{centernot,cancel}

\begin{document}

$\cancel{<:} ~~~~\text{or}~~~~ \centernot{<:}$

\end{document}


Choose a more representative name of what you are talking about with that symbol. Note that the standard is to use \n<relation name> to show the negated symbol of \<relation name>, so you may want to adhere to that.

\documentclass{scrartcl}

\usepackage{centernot,amssymb,mathtools}

\newcommand*\somekindofrelation{\mathrel{<:}}
\newcommand*\nsomekindofrelation{\mathrel{\centernot{<}\vcentcolon}}

\begin{document}

$\gamma \nsomekindofrelation \tau$

\end{document}


EDIT Result: