Math & Science ⇒ Getting theorems to show up on TXC navigator

[ehenning]

I'd like my \newtheorem items to show up in the navigator bar. Right now only \section, \subsection, etc. show up.

My header includes

\documentclass{amsart}
\usepackage{amsmath}

\newtheorem{thm}[subsection]{Theorem}
\newtheorem{defn}[subsection]{Definition}
\newtheorem{prop}[subsection]{Proposition}

\theoremstyle{definition} % Bold headings and Roman body text.
\newtheorem{ex}[subsection]{Example}
\newtheorem{rmk}{Remark}[subsection]

and then in the body

\begin{prop} \label{Sn}
text text text
\end{prop}

\begin{rmk} \label{Purity}
text text text
\end{rmk}

What I'd really like is for the navigator tree to display the labels "Sn" and "Purity." There must be some way to do this.