# What is the LaTeX code for an “open semicolon”

May I know what is the LaTeX code for the following symbol? I can't find it in detexify.

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In which context is this symbol used? Is it a math operator, a symbol to be used in text mode? –  Gonzalo Medina Jul 22 '13 at 14:22
@GonzaloMedina As you probably know by now, this is a math operator, the forward (or sequential) relation composition of Z notation, named after ZF. I would furthermore guess that it is supposed to be a bold/blackboard type/fat semicolon rather than a 9 with a ring above. –  Pål GD Jul 22 '13 at 21:15
The bbold fonts have a semicolon that looks a lot like this. It is a little smaller than \fcmp from the oz package. One can access it with the mathbbol package and \DeclareMathSymbol{\fcmp}{\mathrel}{bbold}{\lq\;}. –  Dan Dec 6 '13 at 3:14
@Dan: that should be the accepted answer, IMHO — the result looks better. –  Blaisorblade Feb 23 at 13:20

According to Shapecatcher, this is a "Z notation relational composition". Looks like you can get it in the objectz package:

\documentclass{article}
\usepackage{oz}
\begin{document}

$\fcmp$

\end{document}


Result:

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For the interested parties, \fcmp is defined as: \def\fcmp{\mathbin{\raise 0.6ex\hbox{\oalign{\hfil$\scriptscriptstyle \mathrm{o}$\hfil\cr\hfil$\scriptscriptstyle\mathrm{9}$\hfil}}}} –  Werner Jul 22 '13 at 17:18

this symbol was added to unicode as Ux2A3E. it should be in the stix fonts.

the latex name is \fcmp.

this name was adopted from a latex package for z notation; the massive update of math symbols in unicode 4.0 (originating with the stix project) incorporated everything from the z notation complement that wasn't already there. the unicode name is "z notation relational composition".

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There's an accent in math mode called \mathring that puts a circle over a character. The circle here is a bit smaller than in your example, so it may or may not be what you are looking for.

\documentclass{standalone}
\begin{document}
$\mathring{9}$
\end{document}


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I don't know a pre-exisiting symbol, but it can be rendered easily enough:

\documentclass{article}
\usepackage{stackengine}
\newcommand\overcirc[1]{\stackon[2pt]{$#1$}{$\circ$}}
\begin{document}
\overcirc{9} \overcirc{7}
\end{document}


I made \overcirc a function that takes an argument.

The above code presents always in \textstyle size. If you needed to use the symbol in subscript or superscript mode, the following would work:

\documentclass{article}
\usepackage{stackengine}
\usepackage{scalerel}
\newcommand\overcirc[1]{\ThisStyle{\stackon[.15ex]{$\SavedStyle#1$}{$\SavedStyle\circ$}}}
\begin{document}
$$\overcirc{9} \overcirc{7}^{\overcirc{3}}$$
\end{document}


The .15ex can be played with to adjust the vertical separation between glyphs.

And if you wanted the circle a different size, putting a \scalebox around it will do so. In this example, I make it 70% of original size.

\documentclass{article}
\usepackage{stackengine}
\usepackage{scalerel}
\newcommand\overcirc[1]{\ThisStyle{\stackon[.15ex]{$\SavedStyle#1$}%
{\scalebox{.7}{$\SavedStyle\circ$}}}}
\begin{document}
$$\overcirc{9} \overcirc{7}^{\overcirc{3}}$$
\end{document}


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Based on Werner's comment to Thomas (that the symbol is in \scriptscriptstyle), it would seem that \newcommand\znrc{\scriptscriptstyle\ThisStyle{\stackon[.15ex]{$\SavedStyle 9$}{$\SavedStyle\circ$}}} would do the trick –  Steven B. Segletes Jul 22 '13 at 19:36