When I have a long proof in a paper that I want to push to another section, I want a theorem-style environment that produces "Proof of ..." and drops a QED symbol at the end. One way to do this is to use amsthm to declare proof environments. Write

\theoremstyle{plain} \newtheorem{thm}{Theorem} \theoremstyle{definition} \newtheorem*{proof1}{Proof of Theorem \ref{Fermat}}

in the preamble, and use the `thm`

environment for the theorem, and then `proof1`

for the proof, and be sure to put `\qed`

at the end of the proof.

If you have a lot of proofs, this is tedious, and the QED symbol at the end is not perfect, particularly when you are ending the proof with a displayed equation and want to use `\qedhere`

. Here is a bit of a hack which does everything we need. The entire example:

\documentclass[a4paper]{article} \usepackage{amsthm} \theoremstyle{plain} \newtheorem{thm}{Theorem} % for use with amsthm % same as proof environment, but with definition-style proof head % and named theorem. \makeatletter \newenvironment{proofof}[1]{\par \pushQED{\qed}% \normalfont \topsep6\p@\@plus6\p@\relax \trivlist \item[\hskip\labelsep \bfseries Proof of #1\@addpunct{.}]\ignorespaces }{% \popQED\endtrivlist\@endpefalse } \makeatother \begin{document} \begin{thm}\label{Fermat} No natural numbers $a,\,b,\,c$ can satisfy the equation $a^n+b^n=c^n$ for integer $n > 2$. \end{thm} We postpone the proof until later. % Time passes... \begin{proofof}{Theorem \ref{Fermat}} (Insert 100 pages of complicated mathematics here.) \end{proofof} \end{document}

As usual, this is too complex for the wiki to parse, but it produces Fermat's last theorem, followed by a definition-style "Proof of Theorem 1", the proof, and then a QED symbol. And you can use `\qedhere`

just as you would in the amsthm `proof`

environment.