# What is this symbol consisting of a horizontal line crossed by a rotated vertial line?

I'm looking at the following symbol, between W and X, in an old PDF file:

and would like to use it in Math mode in my document, but can't figure it out which symbol it is. Is it a standard Math symbol? Any suggestions for symbols that look similar to it?

The PDF file is here: http://dl.acm.org/citation.cfm?id=74833, though it's not open access. The title of the paper is: "Scannerless NSLR(1) parsing of programming languages"

• Do you happen to know the context of this excerpt? If so, please elaborate – Mico Oct 12 '14 at 21:28
• I updated the question. – Wickoo Oct 12 '14 at 21:32
• this could possibly be the unicode symbol 233F -- "apl functional symbol slash bar", although for that symbol, the slash is a lot longer. (the version with the backslash is 2340 -- "apl functional symbol backslash bar".) since the referenced paper is on interpreters and programming languages, apl fits in that category. then the xits fonts would be relevant. – barbara beeton Oct 13 '14 at 14:52

Never seen such a symbol, but you can define it; choose a better name.

\documentclass{article}
\usepackage{centernot}

\newcommand{\wrel}{% for weird relation''
\centernot{\mathrel{-}\joinrel\mathrel{-}}%
}

\begin{document}
$W\wrel X$
\end{document}


Notes. I use the fact that TeX doesn't add space between consecutive relation symbols; \joinrel is a little negative space that counts as a relation symbol. Thus we get two superimposing minus signs (just like what's done for longer arrows). With \centernot we place the \not symbol exactly in the middle.

A different version using / instead of \not, so also \backslash can be employed instead.

\documentclass{article}

\makeatletter
\newcommand{\centersymbol}[2]{%
\mathrel{\vphantom{#1#2}\mathpalette\center@symbol{{#1}{#2}}}%
}
\newcommand{\center@symbol}[2]{%
\center@@symbol{#1}#2%
}
\newcommand{\center@@symbol}[3]{%
\ooalign{\hss$#1\m@th#2$\hss\cr\hss$#1\m@th#3$\hss\cr}%
}
\makeatother

\newcommand{\wrel}{\centersymbol{/}{\mathrel{-}\joinrel\mathrel{-}}}
\newcommand{\lerw}{\centersymbol{\backslash}{\mathrel{-}\joinrel\mathrel{-}}}

\begin{document}
$W\wrel X \lerw Y$
\end{document}


• Thanks! exactly what I wanted. And is there a way to also get the other way around? I mean the crossing bar with 135 degree instead of 45? – Wickoo Oct 12 '14 at 21:41

The package MnSymbol defines \nleftrightline which looks similar:

\documentclass{standalone}
\usepackage{MnSymbol}
\begin{document}
$W \nleftrightline X$
\end{document}


• Usual caveat: \usepackage{MnSymbol} changes all math symbols. – egreg Oct 12 '14 at 22:47