I would like to number a claim within the proof of a theorem, but the proof does not appear right after the statement of the theorem. That is, I would like to generate:
Theorem 1. XXXX
Theorem 2. YYYY
Proof of Theorem 1: ....
Claim 1.1 xxxx
....
I am using thmtools so would prefer to avoid ntheorem.
Here is a possible solution, with a lateproof environment built upon proof, which takes as argument the label corresponding to the theorem we're going to prove.
\documentclass{article}
\usepackage{amsthm,thmtools}
\declaretheorem[
style=plain,
name=Theorem,
]{theorem}
\declaretheorem[
style=plain,
name=Claim,
within=theorem,
]{claim}
\renewcommand{\theclaim}{\thetheorem.\arabic{claim}}
\newenvironment{lateproof}[1]
{%
\renewcommand{\theclaim}{\ref{#1}.\arabic{claim}}%
\begin{proof}[Proof of Theorem~\ref{#1}]%
}
{\end{proof}}
\begin{document}
\begin{theorem}
This theorem is proved just below.
\end{theorem}
\begin{proof}
We do some claims.
\begin{claim}
First claim.
\end{claim}
\begin{claim}
Second claim.
\end{claim}
The proof is complete.
\end{proof}
\begin{theorem}\label{tobeprovedlater}
This theorem is proved later.
\end{theorem}
\begin{theorem}
This is an intermediate theorem.
\end{theorem}
\begin{lateproof}{tobeprovedlater}
We do some claims.
\begin{claim}
First claim.
\end{claim}
\begin{claim}
Second claim.
\end{claim}
The proof is complete.
\end{lateproof}
\end{document}
