Math & Science ⇒ problem renewing proof environment

[peter-andrews]

I am typing a math paper in latex.
I wanted to make a small change in the proof environment,
(just changing the addpunct symbol from . to , so I copied the
\newenvironment{proof} from amsthm.sty into the heading of my paper,
and modified it slightly. However, this produces an error.

Here is a minimal example which latex processes with no problem:

Code: Select all

\documentclass[11pt,dvips,twoside]{book}
\usepackage{amsthm}

\begin{document}

\begin{proof}

obvious.

\end{proof}

\end{document}

Here is the modified file which produces an error:

Code: Select all

\documentclass[11pt,dvips,twoside]{book}
\usepackage{amsthm}

\renewenvironment{proof}[1][\proofname]{\par
  \pushQED{\qed}%
  \normalfont \topsep6\p@\@plus6\p@\relax
  \trivlist
  \item[\hskip\labelsep
        \itshape
    #1\@addpunct{:}]\ignorespaces
}{%
  \popQED\endtrivlist\@endpefalse
}

\begin{document}

\begin{proof}

obvious.

\end{proof}

\end{document}

Here is the error message produced when i run latex on the latter file:

! Undefined control sequence.
\\proof ...pushQED {\qed }\normalfont \topsep 6\p
@\@plus6\p @\relax \trivli...
l.18

? h
The control sequence at the end of the top line
of your error message was never \def'ed.

If latex is not confused by the standard proof environment,
why is it confused now?

Note: On two computers, I found amsthm.sty in the following locations:
/usr/share/texmf-texlive/tex/latex/amscls/amsthm.sty
/usr/share/texmf/tex/latex/amscls/amsthm.sty

[localghost]

You have to present the problem by a full but minimal example [1]. This has to reduced to only relevant code and must be compilable for others as provided.

[1] View topic: Avoidable mistakes


Best regards and welcome to the board
Thorsten