Tomb stone (Q.E.D. mark) is not displayed at the end of a proof when I use "svmono.cls" for my dissertation. How can I enable it?

Here is the code example:

```
<\documentclass[12pt,sectrefs]{svmono}
\usepackage{makeidx}
\usepackage{graphicx}
\usepackage{multicol}
\usepackage[bottom]{footmisc}
\usepackage{amsmath}
\usepackage{lipsum}
\makeindex
\begin{document}
\frontmatter
\mainmatter
\chapter{Chapter Heading}
\section{Section Heading}
\subsection{Subsection Heading}
\begin{theorem}
\lipsum[1-2]
\end{theorem}
\begin{theorem}
nonses\\
nonsesnse\\
nonsesnse\\
nonsesnse\\
nonsesnse\\
%nonsesnse\\
\end{theorem}
\begin{proof}
here is the proof.
\end{proof}
\end{document}
```

## Best Answer

The

`proof`

environment provided by`svmono`

does not include the automatic QED symbol. Instead it provides a clumsy method for manually adding a tombstone.You can solve the issue by loading

`amsthm`

, so long as you continue to use`svmono`

methods for defining new theorem-like environments.