# 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.

• In which context is this symbol used? Is it a math operator, a symbol to be used in text mode? Jul 22, 2013 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. Jul 22, 2013 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, 2013 at 3:14
• @Dan: that should be the accepted answer, IMHO — the result looks better. Feb 23, 2015 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:

• 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, 2013 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".

The best result I've found so far is the symbol \fatsemi from the package stmaryrd.

When compared with \fcmp mentioned above, the document

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

$\fatsemi$ vs $\fcmp$

\end{document}


renders as

• Could you please post some output to make it easier for people to see how it looks? Aug 18, 2017 at 15:23

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}


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}


• 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 Jul 22, 2013 at 19:36