# Defining a null environment

I am writing a mathematical document and I want to make a overview document, in which I only present the theorems and definitions and not the proofs, so I thought that I can change the environment proof to a null environment, which basically ignores the proofs or replaces them with one single space, or anything similar. I thought using the comment package and tried \renewenvironment{proof}{\begin{comment} }{ \end{comment}} but as it turns out LaTeX interprets }{ as comment.

How can I achieve this neatly or is there a way to turn the proof off by amsmath?

• You need to use \in­clude­com­ment{proof}... – Werner Apr 27 '16 at 17:05
• When I do that I get inputenc error. I use German characters like ü and ß in the proofs. – Gonenc Apr 27 '16 at 17:56
• @Werner -- this sounded like such a good idea. but with amsthm, all that is omitted are the proof headers and qed marker; the text remains. (i will write to the author.) – barbara beeton Apr 27 '16 at 18:10
• @gonenc -- amsmath shouldn't figure into this. it's amsthm that formats theorems, and i've just determined that this doesn't work (at least not if i've used the same comment package that you did). – barbara beeton Apr 27 '16 at 18:12
• You might also look at the envrion package, which would use \RenewEnviron{proof}{\begin{comment}\BODY\end{comment}} – John Kormylo Apr 27 '16 at 19:08

Perhaps this is a solution: \gobble the content away with a \RenewEnviron{proof}{}{} that has no \BODY command, i.e. the \BODY is 'thrown away'.

I used the first proof environment to show some content and then redefined proof, the second content isn't display any longer then.

\documentclass{article}

\usepackage{amsthm}

\usepackage{environ}

\begin{document}

\begin{proof}
Brontosaurs were large
\end{proof}

\RenewEnviron{proof}{%
% How not to be seen?
}{}

\begin{proof}
Brontosaurs were large
\end{proof}

\end{document}