-% Define a new ``partsecframe'' environment that uses a default frame
-% title of ``<part>: <section>'' when no other frame title is given.
-\newenvironment{partsecframe}[1][%
- \ifx\insertpart\@empty%
- \else%
- \insertpart: %
- \fi%
- \insertsectionhead%
-]
- {\begin{frame}{#1}\vskip1em\par}
- {\end{frame}}
-