# Tombstone symbol

I would like to change the predefined tombstone symbol to the first one on the website http://en.wikipedia.org/wiki/File:Halmos.png (the square in a black frame).

How can I do it, please?

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Isn't it the default? –  egreg May 22 '12 at 13:14
You said "the predefined symbol", but we need to see how you build your theorem-like structures, because when using amsthm the predefined symbols is precisely the one you want. –  Gonzalo Medina May 22 '12 at 13:46
@egreg -- the default depends on the document class or theorem package used. also, i don't believe that there is a bold open square. all the "box" symbols in the comprehensive symbols list have thin walls, as in the second symbol shown. –  barbara beeton May 22 '12 at 13:57
I'm using the amsthm package as well, but the predefined symbol for the end of any proof looks almost like the second one on the picture above - square with thin walls. I would like to put in my work exactly the same as the first one-square with thick walls. –  Jane May 22 '12 at 14:14

## 1 Answer

Since you are using amsthm, you need to redefine the \qedsymbol (in the preamble of your document if the change must apply to all the document). One option would be to use the \Squarepipe command from the marvosym package; here's a simple example:

\documentclass{article}
\usepackage{amsthm}
\usepackage{marvosym}

\renewcommand\qedsymbol{\Squarepipe}

\begin{document}

\begin{proof}test\end{proof}

\end{document}


Of course, you can define your own square; here's a comparison between the default symbol, the \Squarepipe command from marvosym and a customized \BoldSquare newly defined (you can change the values for \fboxrule and the arguments of \rule according to your needs):

\documentclass{article}
\usepackage{amsthm}
\usepackage{marvosym}

\newcommand\BoldSquare{%
\setlength\fboxrule{1.1pt}\setlength\fboxsep{0pt}\fbox{\phantom{\rule{5pt}{5pt}}}}

\begin{document}

\begin{proof}test\end{proof}
\renewcommand\qedsymbol{\Squarepipe}
\begin{proof}test\end{proof}
\renewcommand\qedsymbol{\BoldSquare}
\begin{proof}test\end{proof}

\end{document}


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@Jane in that case, please edit your question and add a simple (but complete) document showing how you are using my definition and illustrating that it is not working. –  Gonzalo Medina May 22 '12 at 16:11
@Jane the last one was obtained with the settings of my example... Would you like us to continue the discussion in a chat room? That will allow us to detect and correct your problem quickly... –  Gonzalo Medina May 22 '12 at 16:35
–  Gonzalo Medina May 22 '12 at 16:35
@Jane if you want to, please follow the link in the above comment (the one with "continue this discussion in chat") and we can quickly solve your problem. –  Gonzalo Medina May 22 '12 at 16:44