Is there an "endproof" package?

Question

You may be familiar with the endfloat package, which moves all figures and tables to the end of your document.

Is there a similar package for achieving that kind of results with proof environments (as defined in the amsthm package)? For instance, the following chunk:

Theorem 1: some wonderful statement.

Proof: some astonishing proof.

would appear (when the package is used) in the text as:

Theorem 1: some wonderful statement.

Proof: see page P.

and then page P would contain something like:

Proof of Theorem 1 page XXX: some astonishing proof.

Answer 1

You can try with the code shown in this answer but changing the definition of \proofatend with

\long\def\proofatend#1\endproofatend{%
  \proof See page \pageref{pr\pat@label}.\endproof
  \edef\next{\noexpand\begin{proof}[Proof of \pat@label]\noexpand\label{pr\pat@label}}%
  \toks\numexpr\prooftoks+\value{proofcount}\relax=\expandafter{\next#1\end{proof}}
  \stepcounter{proofcount}}

This will put Proof. See page nnn. after the statement.

If you prefer to write proofs in environment form, then load also the environ package and write, instead of the definition of \proofatend before the following:

\NewEnviron{proofatend}
  {\proof See page \pageref{pr\pat@label}.\endproof
  \edef\next{\noexpand\begin{proof}[Proof of \pat@label]\noexpand\label{pr\pat@label}}%
  \toks@=\expandafter{\next}%
  \global\toks\numexpr\prooftoks+\value{proofcount}\relax=
    \expandafter{\the\expandafter\toks@\BODY\end{proof}}%
  \stepcounter{proofcount}}

Then you may write your proofs as

\begin{lem}\label{addition}
$1+1=2$
\end{lem}
\begin{proofatend}
It's quite clear.

Here's a paragraph break.
\end{proofatend}