# superimosing {\circ} on {\sum} in {math-mode} [duplicate]

Possible Duplicate:
\subseteq + \circ as a single symbol (“open subset”)

Is it possible to superimpose a variable size \circ on \sum to compose a symbol just like \oint?

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## marked as duplicate by clemens, ienissei, Seamus, Stephen, WernerNov 17 '12 at 1:39

Welcome to TeX.sx! A tip: You can use backticks  to mark your inline code – Corentin Nov 16 '12 at 14:46
This question is very similar to \subseteq + \circ as a single symbol (“open subset”). Please take a look at it as the information there might help you. If so, that's great, and we'll probably close this question as a duplicate just to keep the place tidy and to help people find answers quickly. If not, please edit your question here to explain why so that people can better focus their attention to help you. – Werner Nov 16 '12 at 14:52
This question might also be useful to you. – Seamus Nov 16 '12 at 16:23

## LuaTeX/XeTeX with XITS Math

The symbol ⨊ is Unicode character U+2a0a Modulo two sum. It can be used directly with LuaTeX or XeTeX if the glyph is supported by the used fonts. Example:

\documentclass{article}
\usepackage{unicode-math}
\setmathfont{XITS Math}
\begin{document}
$⨊$ % or \modtwosum
\end{document}


## Package fdsymbol

Another font that directly provides the symbol is fdsymbol:

\documentclass{article}
\usepackage{fdsymbol}
\begin{document}
$\modtwosum$
\end{document}


## Superimposing

It is also possible to superimpose the symbols, for example:

\documentclass{article}

\makeatletter
\newcommand*{\modtwosum}[1][.4]{%
\mathop{%
\mathpalette\@modtwosum{#1}%
}%
}
\newcommand*{\@modtwosum}[2]{%
\sbox0{$\m@th#1\sum$}%
\rlap{%
\hbox to \wd0{%
\hspace{0pt plus #2fil}%
$\m@th#1\circ$%
\hspace{0pt plus 1fil}%
\hspace{0pt plus -#2fil}%
}%
}%
{#1\sum}%
}
\makeatother

\begin{document}
$\modtwosum$
$\def\test#1{\modtwosum[#1]_{#1}} \test{0}\test{0.2}\test{0.4}\test{0.6}\test{0.8}\test{1}$
\end{document}
`

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