# Recall a theorem in a different section of a chapter

I am aware that this question has been asked before and I did refer to the previous answers given unfortunately I keep getting errors when I compile.

Here's my minimum preamble

\usepackage{amsmath}
\usepackage{amsthm}
\usepackage{amssymb}
\usepackage{hyperref}
\usepackage{cleveref}
\theoremstyle{definition}
\newtheorem{my}{Theorem}[section]

\begin{document}

\section{First}

\begin{restatable}
\label{thm:Eprime}
Suppose $q \neq 2, 3, 17$ is a prime with $2kP_\star=\infty \in E(\mathbb{F}_q)$ but $kP_\star \neq 0, T_\star$.
\end{restatable}

\section{Second}

We recall \cref{thm:Eprime}

Then in Section 2, I want to recall this theorem together with it’s statement without changing the numbering.

I tried using \usepackage{thmtools} and \usepackage{thm-restate}, but it just seems not to work. When I compile, it gives an error. Not sure why.

• Which errors? Especially, please post the exact first error you get. Please also post a complete minimal document. Mere fragments of code do not make it easy to understand your question or to try solving it. A complete example which compiles to produce the problematic output is needed. Or, as in this case, an example which produces the mystery error you are asking about when we try to compile it. – cfr Jan 16 '16 at 3:12
• At a guess, load amssymb. – cfr Jan 16 '16 at 3:12
• I do have amssymb in my preamble. I am writing up my thesis and have so many things in my preamble that I mistakenly forgot to place it here. – shahrina ismail Jan 16 '16 at 3:21
• That is why you need to provide a minimal not working example. Just make a small, complete document which produces the error. Whatever it is. Right now, it is still a complete mystery. I completed your fragments in the obvious way, produced an error, reduced the example and explained the problem. That's why you need to produce the example and not us - because you know what problem you're having and we can only guess. – cfr Jan 16 '16 at 3:25
• That's not a minimal example, but the error says what is wrong. You are using an environment you've not defined. restatable is unknown. Did you load a package which is meant to define it? Did you define it somewhere? Are you sure it is not restateable? – cfr Jan 16 '16 at 4:22

Minimal example:

\documentclass{article}
\usepackage{amsmath,amsthm}
\begin{document}
$\mathbb{A}$
\end{document}

produces the following error when an attempt is made to compile it:

! Undefined control sequence.
l.7   \mathbb
{A}
? x

This is because \mathbb is not a standard LaTeX command and is not defined by either of the loaded packages. Add

\usepackage{amssymb}

to enable it and resolve the error.

• I do have amssymb in my preamble. I am writing up my thesis and have so many things in my preamble that I mistakenly forgot to place it here. I have edited my code. – shahrina ismail Jan 16 '16 at 3:23