symbols
Possible Duplicate:
How to look up a symbol?
The instructor of a statistics and probability course uses an odd (to me) symbol for logical negation. The symbol is not a tide (~) or an exclamation mark (!) or the bar-over symbol. This symbol looks like the top right hand corner of a rectangle. What is this symbol called?
You can overlay the symbols the following way: Box the wider one and let the other one lap over it (using \rlap or \llap). The correct centering is achieved by placing the second character into a box with the equal width but using \hss to center it. The correct size for the different math modes can be adjusted using \mathchoice.
\documentclass{article}
\def\qeq{\mathrel{%
\mathchoice{\QEQ}{\QEQ}{\scriptsize\QEQ}{\tiny\QEQ}%
}}
\def\QEQ{{%
\setbox0\hbox{=}%
\rlap{\hbox to \wd0{\hss?\hss}}\box0
}}
\textwidth=2cm
\begin{document}
$ A \qeq B $
$ A = B $
\[ A \qeq B \]
\[ A = B \]
$ S_{ A \qeq B } $
$ S_{ A = B } $
$ S_{S_{ A \qeq B }} $
$ S_{S_{ A = B }} $
\end{document}
Something like
\def\hmm{>\joinrel\relbar\joinrel<}
$a \hmm b
perhaps?
Best Answer
I have seen that symbol rather frequently and is a popular mathematical notation. AFAIK
~and!are more popular in computer science/engineering, because there is an actual symbol for that on the keyboard.:)The symbol is defined in math mode as\neg.