# Double \prec as a single symbol?

We have < and \ll. What about double \prec, i.e. something like \prec\prec but with spacing as in \ll?

Remark. I could not find an answer in http://detexify.kirelabs.org/classify.html or http://www.ctan.org/tex-archive/info/symbols/comprehensive/. I am not interested, how to construct this symbol from two \prec's (I know how to reduce the distance), but I am searching for a symbol from some package, even so strange as MnSymbol.

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STIX Math (or XITS Math), Asana Math and Lucida Bright Math have it (U+2ABB); probably also Cambria Math. It's not included in the TeX Gyre Unicode math fonts. – egreg Sep 1 '14 at 8:51
@egreg Your comment is a valuable answer for me, so transforming it into an answer would be probably useful for next seekers. – Przemysław Scherwentke Sep 1 '14 at 9:12
This question and tex.stackexchange.com/questions/149052/variation-on-prec-prec do seem to have quite a bit of overlap: would it be OK to merge? I'd hope that some of the answers will be useful to you and I can see that both questions do seem to cover the 'single symbol' part at least in principle. – Joseph Wright Sep 1 '14 at 12:49

The mathb font (from mathabx) has an \llcurly and a \ggcurly symbols. Here is how to use them without loading the whole package:

\documentclass[12pt]{article}
\usepackage[utf8]{inputenc}

\DeclareFontFamily{U}{mathb}{\hyphenchar\font45}
\DeclareFontShape{U}{mathb}{m}{n}{
<-6> mathb5 <6-7> mathb6 <7-8> mathb7
<8-9> mathb8 <9-10> mathb9
<10-12> mathb10 <12-> mathb12
}{}
\DeclareSymbolFont{mathb}{U}{mathb}{m}{n}
\DeclareMathSymbol{\llcurly}{\mathrel}{mathb}{"CE}
\DeclareMathSymbol{\ggcurly}{\mathrel}{mathb}{"CF}
\begin{document}

$a \llcurly b \quad a \ggcurly b$

\end{document}


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Oh, "parallel" curved lines look much better then a simple translation of \prec! – Przemysław Scherwentke Sep 1 '14 at 12:18
Is this line really necessary: \def\blueDiamond{\mathbin{\color{SteelBlue3}\blacklozenge}} ? – Rauni Dec 19 '14 at 12:04
@Rauni: That's right. I think I took the preamble from a previous code for an answer to a more less related question and forgot to check what had to be deleted. It's removed now. Thanks for pointing that. – Bernard Dec 19 '14 at 12:09
Glad to help :) – Rauni Dec 19 '14 at 12:22
According to tex.stackexchange.com/a/218683/23484, it should be "mathb5", not "mathab" (right after <-6>). – Rauni Dec 19 '14 at 12:25

The unicodes are U+2ABB and U+2ABC. Here are some examples with the fonts I am having available (in order of increasing uglyness):

% arara: lualatex

\documentclass{article}
\usepackage{unicode-math}
\newcommand*{\test}{\ensuremath{\prec\Prec\Succ\succ}}

\begin{document}
\setmathfont{code2000.ttf}\test

\setmathfont{xits-math}\test

\setmathfont{asana-math}\test

\setmathfont{quivira.otf}\test

\setmathfont{symbola.ttf}\test

%\setmathfont{cambria-math}\test % not on my system
\end{document}


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Here's a homemade construction.

\documentclass{article}
\usepackage{graphicx}
\def\pprec{\mathrel{\scalebox{.9}[1]{$\prec$}\mkern-5mu%
\scalebox{.4}[1]{$\prec$}\mkern-5.5mu\scalebox{.4}[1]{$\prec$}}}
\begin{document}
$a \pprec b$
\end{document}


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