samcarter
How to automatically add symbols to other theorem environments, similar to the qed symbol at the end of a proof?
```
\documentclass{beamer}
\begin{document}
\begin{frame}
\begin{theorem}
content...
\end{theorem}
\begin{lemma}
content
\end{lemma}
\begin{proof}
content...
\end{proof}
\end{frame}
\end{document}
```
Top Answer
samcarter
One can use the `theorem begin` and `theorem end` templates to smuggle in a thm symbol, which can then be adjusted for each environment:
```
\documentclass{beamer}
\setbeamertemplate{thm symbol}{}
\addtobeamertemplate{theorem begin}{
\def\qedsymbol{\leavevmode\hbox{\usebeamertemplate*{thm symbol}}}%
\pushQED{\qed}%
}{}
\addtobeamertemplate{theorem end}{\popQED}{}
\AtBeginEnvironment{lemma}{
\setbeamertemplate{thm symbol}{Quack}
}
\AtBeginEnvironment{theorem}{
\setbeamertemplate{thm symbol}{\color{gray}$\blacktriangle$}
}
\begin{document}
\begin{frame}
\begin{theorem}
content...
\end{theorem}
\begin{lemma}
content
\end{lemma}
\begin{proof}
content...
\end{proof}
\end{frame}
\end{document}
```
