【LaTeX Tips】如何复写定理

在书写定理时，我们可能会将定理的结论写在前面，而后展开对它的讨论。定理复杂的证明过程，通常会放在后文的附录中。这时候，我们就需要复写这个定理。

下面这个来自 TeX.SX 的方法由 lockstep 提供。

\documentclass{article}

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

\usepackage{hyperref}

\usepackage{cleveref}

\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}

\section{Second}

We recall \cref{thm:goldbach}:

\goldbach*

\end{document}

thmtools 包里的 thm-restate 子包提供了 restatable 环境。下面的例子里，借用了 hyperref 宏包（超链接）和 cleveref 宏包（提供了 \cref 宏，可以加载正确的定理样式）。具体可以查看 thmtools 宏包文档的 1.4 节。

效果：

We sometimes hope that we could show and discuss a theorem, without proof it. However, in appendix, we mey need to recall that theorem and then write down the details of proof.

The following context comes from TeX.SX that is provided by lockstep.

\documentclass{article}

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

\usepackage{hyperref}

\usepackage{cleveref}

\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}

\section{Second}

We recall \cref{thm:goldbach}:

\goldbach*

\end{document}

The thm-restate package which is part of thmtools offers a restatable environment. In the following example, I also use hyperref and cleveref (its \cref macro automatically adds the correct theorem type). See section 1.4 of the thmtools manual for details.

效果：