# Triangle inequality symbol

Does anybody know what symbol to put above an inequality symbol < to indicate that the triangle inequality has been applied?

I would like a symbol like this (which is not in The Comprehensive Latex Symbol List)

And I tried the following

\mathrel{\triangle\!\!\!\!/}


but the two lines are not parallel:

Does anybody know how to somehow rotate the line to the correct angle? Any help is appreciated!

• First, search ctan.org/tex-archive/info/symbols/comprehensive – John Kormylo Mar 28 '15 at 14:56
• Do you use the triangle inequality so many times that you need a special symbol instead of simply adding the words? Such stenography is not really useful, in my opinion. – egreg Mar 28 '15 at 14:56
• @egreg Yes, actually I do :). I don't like writing 'the triangle inequality' everywhere, but I really need to somehow show that it is being used. – Carucel Mar 28 '15 at 14:59
• Try \mathrel{\ooalign{\hidewidth$\triangle$\hidewidth\cr\rotatebox[origin=c]{-9}{$/$}\cr}}. – user11232 Mar 28 '15 at 15:01
• @HarishKumar Your solution works as well, thank you! – Carucel Mar 28 '15 at 15:05

Here is a tikz picture

\documentclass{article}
\usepackage{tikz}
\DeclareRobustCommand\trineg{%
\begin{tikzpicture}[baseline,scale=.07]
\draw (0,0) -- (4,0) -- (2,3.46410161514) -- cycle;
\draw [domain=1:3.4] plot(\x,{(5.6-3.46410161514*\x)/-2});
\end{tikzpicture}}
\begin{document}
$\mathrel{\triangle\!\!\!\!/}$ test \trineg\ test $\trineg$
\end{document}