limits to \oplus not working and double ended arrow equation

I am having an equation which having \oplus with limits, but \limits for \oplus gives error and there is another critical equation with double ended arrow. can anyone please help me to key this equation.

• Please add a minimal working example (MWE) that illustrates your problem. It will be much easier for us to reproduce your situation and find out what the issue is when we see compilable code, starting with \documentclass{...} and ending with \end{document}. Aug 21 '13 at 9:55
• people spend their day writing that comment but even google understands what the OP asks for (since it directed me to that page)!! \documentclass is NO NEED!! Mar 6 '15 at 18:31

There is a larger \bigoplus that acts as operator. Or \oplus can be wrapped in \mathop:

\documentclass{article}
\usepackage{amsmath}
\begin{document}
$\bigoplus_{\substack{\rho\in g,\\\rho \neq \rho_0}}$
$\mathop{\oplus}_{\substack{\rho\in g,\\\rho \neq \rho_0}}$
\end{document}


This is a job for a graphic tool, for example tikz-cd:

\documentclass{article}
\usepackage{tikz-cd,amsmath,amssymb}

\begin{document}

$\begin{tikzcd}[row sep=2pt] {} & \mathrm{VI} \arrow{r} & \mathrm{X} \\ {} \\ \smash[b]{\bigoplus\limits_{\substack{\rho\in\mathfrak{g}\hat{\,}\\\rho\ne\rho_{0}}}} \vphantom{\bigoplus} \mathrm{V} \arrow{uur} \arrow{ddr} \\ {} & & \mathrm{VIII} \arrow{uuu} \\ {} & \mathrm{VII} \arrow{ur} \arrow{dr} \\ {} & & \mathrm{IX} \end{tikzcd}$

\end{document}


The subscripts are smashed out, because otherwise they would make an arrow start too low. Notice \substack for the two row subscript.

You can make the diagram even more compact with row sep=-4pt

As suggested by Qrrbrbirlbel, the \smash trick can be avoided:

\begin{tikzcd}[row sep=-4pt]
{} & \mathrm{VI} \arrow{r} & \mathrm{X} \\
{} \\
|[text depth=+0pt]|\bigoplus\limits_{\substack{\rho\in\mathfrak{g}\hat{\,}\\\rho\ne\rho_{0}}}
\mathrm{V}
\arrow{uur} \arrow{ddr} \\
{} & & \mathrm{VIII} \arrow{uuu} \\
{} & \mathrm{VII} \arrow{ur} \arrow{dr} \\
{} & & \mathrm{IX}
\end{tikzcd}

• Without \smash and \vphantom (ignoring all possible depths): |[text depth=+0pt]| \bigoplus\limits_{…} \mathrm{V} <arrows> Aug 21 '13 at 10:08
• hi for this code im getting output like lengthy arrows which exceeds page corners . im not getting the same displayed output
– ravi
Aug 22 '13 at 5:36
• @ravi Maybe you have an outdated version of tikz-cd Aug 22 '13 at 7:31
• im using miktex for files . dont know how to update tikz-cd
– ravi
Aug 26 '13 at 8:01