I want to add three braces to a xymatrix in a xypic environment. Here's how I got so far.
\documentclass[11pt]{article} % use larger type; default would be 10pt
\usepackage[all]{xy}
\begin{document}
\xy
\xymatrix@C=10pt@R=20pt{
&\\
& A_1\POS*\frm{^\}},+U*++!D\txt{A to B} & B_2 & C_3 \POS*\frm{^\}},+U*++!D\txt{C to D} & D_4\\
& E_5 & F_6 \POS*\frm{_\}},+U*++!D\txt{F to G} & G_7 & H_8
}
\endxy
\end{document}
Now there are two issues:
I want the braces to span from A to B, C to D and the one at the bottom from F to G. At the moment, they only embrace a single element. How can I do this using the xymatrix [rr] syntax?
I want to add the label for the bottom brace from below. At the moment, it is still displayed on top.
I appreciate any comments on this issue!