# bigsqcup with sideset doesn't shrink in subscript

I'm using a \bigsqcup that involves a \sideset inside a subscript for a function, but the \bigsqcup symbol doesn't get smaller like everything else. Is there a way to make it shrink proportionally with the other symbols while using \sideset?

Here's a self contained example:

\documentclass{article}
\usepackage{amsmath}
\usepackage{amssymb}

\begin{document}
\begin{equation*}
\bigsqcup_{\sideset{}{_B}\bigsqcup V} A
\end{equation*}
\end{document}


It displays like this:

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I think this question may be illformed. This may be a consequence of the environment that I'm using. This is inside a mathpar from the mathpartir package and there is a sideset in affect on the \bigsqcup. I'm still investigating. –  Arlen Cox Dec 22 '12 at 4:29
Apparently this has something to do with \sideset. –  Arlen Cox Dec 22 '12 at 4:30
I get two different sizes with: \bigsqcup A_{\bigsqcup}. It would be helpful if you composed a fully compilable MWE including \documentclass and the appropriate packages that sets up the problem. While solving problems is fun, setting them up is not. Then those trying to help can simply cut and paste your MWE and get started on solving problem. –  Peter Grill Dec 22 '12 at 4:43
Exact code is too complex. Way too many macros. I've added a distilled version. It is definitely sideset related, so the question is updated with that information. –  Arlen Cox Dec 22 '12 at 6:41

The point is that \sideset just isn't designed to be used in sub- and superscripts: it issues an explicit \displaystyle in which the big operator will be typeset. In your case, you can just use \bigsqcup_B V in the subscript, as Peter suggests in his comment. The B is set at the side since it's in a subscript. (In other cases, you can use \bigsqcup\nolimits_B V.)

\documentclass{article}
\usepackage{amsmath}
\usepackage{amssymb}

\begin{document}
\begin{equation*}
\bigsqcup_{\bigsqcup_B V} A
\end{equation*}
\end{document}

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