Changing the Label Font Size for xypic Commutative Diagrams

Question

I'm using xymatrix in the xypic package to draw commutative diagrams and I would like for the math in the arrow labels to use the same font size as the math in the rest of the document. Is there an easy way to accomplish this? I've tried various tex commands for locally changing the font size but these don't seem to help. For example,

\documentclass[11pt,letterpaper, oneside]{book}
\usepackage{amsmath}
\usepackage{xypic}
\begin{document}
\xymatrixcolsep{5pc}\xymatrixrowsep{5pc}\xymatrix{
X \ar[d]_{\pi} \ar[rd]^f \\
X/\sim \ar[r]_{\xoversim{f}} & Y
}
\end{document}

produces symbols on the arrow labels that are considerably smaller than the other math symbols in the document. This is understandable since one uses subscript and superscript notation to indicate the labels but results in labels that are difficult to read.

Answer 1

\[
\renewcommand{\labelstyle}{\textstyle}
\xymatrix@R=5pc@C=5pc{
X \ar[d]_{\pi} \ar[rd]^f \\
X/\sim \ar[r]_{\xoversim{f}} & Y
}
\]

I suggest to leave the setting of \labelstyle inside the math environment, unless you want that all diagrams inherit this setting. Notice a simpler way to specify row and column separation.