[Tex/LaTex] using a restatable before it is stated

Question

This question is related to the question at Recalling a theorem, which uses the thmtools and thm-restate packages and the restatable environment to define a theorem that can be re-stated later on.

Is it possible to refer to something that is defined later on?
In an earlier chapter, I have some discussion that is referring to a definition that is defined properly in a later chapter, but I can't reuse the definition before it is defined…

For example, when I do the following

\documentclass{article}
\usepackage{thmtools} 
\usepackage{thm-restate}

\declaretheorem[name=Theorem,numberwithin=section]{thm}

\begin{document}

\section{First}

\goldbach*

\begin{restatable}[Goldbach's conjecture]{thm}{goldbach}
\label{thm:goldbach}
Every even integer greater than 2 can be expressed as the sum of two primes.
\end{restatable}

\end{document} 

I get an error –

undefined control sequence \goldbach

Is there any way to export these definitions so that they can be referred to before they are actually defined…?

Answer 1

Do it the other way round, using the restatable* environment.

\documentclass{article}
\usepackage{thmtools} 
\usepackage{thm-restate}
\usepackage{lipsum}

\declaretheorem[name=Theorem,numberwithin=section]{thm}

\begin{document}

\section{First}

\begin{restatable*}[Goldbach's conjecture]{thm}{goldbach}
\label{thm:goldbach}
Every even integer greater than 2 can be expressed as the sum of two primes.
\end{restatable*}

\lipsum[2]

\begin{thm}
One
\end{thm}

\lipsum[3]

\begin{thm}
Two
\end{thm}

\lipsum[3]

\goldbach

\lipsum[3]


\end{document}