%% 
%%  An UIT Edition example
%% 
%%  Example 04-15-2 on page 107.
%% 
%%  Copyright (C) 2012 Vo\ss 
%% 
%%  It may be distributed and/or modified under the conditions
%%  of the LaTeX Project Public License, either version 1.3
%%  of this license or (at your option) any later version.
%% 
%%  See http://www.latex-project.org/lppl.txt for details.
%% 

% Show page(s) 1

%% ==== 
\PassOptionsToClass{}{beamer}
\documentclass{exabeamer}
\usepackage[utf8]{inputenc}

%\StartShownPreambleCommands
\usetheme{Hannover}
%\StopShownPreambleCommands

\begin{document}
\begin{frame}{Pythagoras's Theorem}
\begin{align}
 c^2 &= a^2+b^2     \label{Pythagoras's Theorem}\\
 c^2 &= a^2+b^2-2ab\cos\gamma
                    \label{Law of Cosines}
\end{align}
foo \uncover<2>{bar}

\only<3>{Doesn't make sense without an overlay
  specification!\label<3>{label}}
\end{frame}
\end{document}