# Creating a \precneq symbol

Going through the comprehensive symbols list, and also Detexify, we see that through various packages (mostly amssymb) we can get the symbols

• \prec Precedes. Unicode U+227A: ≺
• \preceq Precedes or equals to. Unicode U+227C: ≼
• \precsim Precedes or equivalent to. Unicode U+227E: ≾
• \precnsim Precedes and not equivalent to. (I don't think there is a unicode symbol for this one) Edit: as David Carlisle points out I just didn't scroll down far enough. It is Unicode U+22E8.

Its cousin < supports variants \leq and \lneq. Evidently, however, there is no \precneq equivalent for the "precedes" symbol.

Question: Has someone already constructed the symbol and placed it in a package? If not, how can I construct such a symbol? It should start from the AMS \preceq symbol and drop a cancelling sign over the equals-to part only.

Edit: for clarification, something like the following is what I desire:

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In the amssymb package there is a \npreceq symbol. – Count Zero Jun 7 '12 at 8:34
Arguably one should only use \prec to mean precedes and not equals to and \preceq for the possibility of equals to. In which case the symbol would not be necessary. But sometimes in the text it is nice to emphasize the fact that A precedes B and not equals to B. – Willie Wong Jun 7 '12 at 8:34
@CountZero: \npreceq cancels the whole symbol. I just want the canceling line to drop over the equals part similar to \precnsim or to \lneq (also from amssymb). – Willie Wong Jun 7 '12 at 8:35
I edited your question to make it clearer what you exactly need. Hope that's ok with you. – Count Zero Jun 7 '12 at 8:38
well, i lied in my previous comment. this symbol is in unicode, at Ux2AB1, and thus should be in the stix fonts. those aren't really well documented yet, but a comment by khaled hosny on april 5, regarding this question, states that "TeX support for STIX fonts is well under way, stay tuned ;)" – barbara beeton Jun 7 '12 at 20:02

Lost symbol sighted in mathabx. :)

\documentclass{article}
\usepackage{mathabx}
\begin{document}
$\precneq$
\end{document}


EDIT: A nice resource in such cases, the Comprehensive Symbol List. I admit, at times it can be quite tedious browsing it for a given symbol... but so far it's the best thing I know of.

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With a pointer to this question if one doesn't want to load the whole mathabx (which changes many symbols). This symbol is in slot "AC of mathb. – egreg Jun 7 '12 at 9:10
Hah, I did check the CSL, but I missed the mathabx section for negated binary relations. Thanks! – Willie Wong Jun 7 '12 at 9:22
@WillieWong: Can happen to anyone. ;) – Count Zero Jun 7 '12 at 9:24

U+22E8 is PRECEDES BUT NOT EQUIVALENT TO

Although the reference glyph has a negated wavy line rather than a negated straight line

Other information about that character from the source of that document:

  <character id="U022E8" dec="8936" mode="math" type="relation">
<unicodedata category="Sm" combclass="0" bidi="ON" mirror="Y" mathclass="R"/>
<afii>21B1</afii>
<latex>\precedesnotsimilar </latex>
<Elsevier grid="blr" ent="prnsim">
<desc>precedes, not similar</desc>
</Elsevier>
<AMS>\precnsim</AMS>
<APS>prnsim</APS>
<Wolfram>NotPrecedesTilde</Wolfram>
<entity id="prnsim" set="8879-isoamsn">
<desc>/precnsim N: precedes, not similar</desc>
</entity>
<entity id="prnsim" set="9573-1991-isoamsn">
<desc>/precnsim N: precedes, not similar</desc>
</entity>
<entity id="prnsim" set="9573-2003-isoamsn">
<desc>/precnsim N: precedes, not similar</desc>
</entity>
<entity id="precnsim" set="mmlalias">
<desc>alias ISOAMSN prnsim</desc>
</entity>
<font name="hlcra" pos="235"/>
<operator-dictionary form="infix" lspace="5" rspace="5" priority="265"/>
<description unicode="1.1">PRECEDES BUT NOT EQUIVALENT TO</description>
</character>

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Thanks! You tracked down the unicode character for \precnsim (I edited the question to reflect that find). But that is not quite what I am looking for. – Willie Wong Jun 7 '12 at 9:19

Here the unicode solution with use of and the font you like:

% arara: lualatex

\documentclass{article}
\usepackage{fontspec}
\usepackage{booktabs}
\usepackage{caption}
\newcommand*{\test}[1]{{\fontspec{#1}\symbol{"2AB1}}}
\textwidth=6.5cm

\begin{document}
\begin{table}
\centering
\caption{U+2AB1 -- PRECEDES ABOVE SINGLE-LINE NOT EQUAL TO}
\begin{tabular}{ll}\toprule
Font & Symbol\\\midrule
Code2000 & \test{code2000.ttf}\\
Quivira & \test{quivira.otf}\\
STIX Math & \test{STIX Math}\\
Symbola & \test{symbola.ttf}\\\bottomrule
\end{tabular}
\end{table}
\end{document}


And here are two more fonts with help of the package :

% arara: lualatex

\documentclass{article}
\usepackage{unicode-math}

\begin{document}
\setmathfont{XITS Math}
$A\precneq B\succneq C$

%\setmathfont{Cambria Math} % not available on my system
%$A\precneq B\succneq C$

\setmathfont{Asana Math}
$A\precneq B\succneq C$
\end{document}


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