我计划将扩展摘要作为论文的前言（我使用 cleanthesis），其中包含主要结果的陈述（定理、命题等）。
我希望它们出现在扩展摘要中，使用相同的编号（章节.部分.环境），并链接到论文中的原始陈述。也就是说，我想要一份序言中陈述的精确副本，但不包括与原始陈述的链接。
经过一番研究，我发现 thmtools 的 thm-restate 包提供了此功能。问题是我需要将原始语句保留在主论文中；也就是说，我需要调用出现在原始语句“之前”，然后我得到了一个编译错误：“！未定义的控制序列。”
我该如何修复此问题？
（我不知道这是否相关，但该文档被分成不同的文件：本质上，第一个文件对应于序言，然后每个章节一个文件。）
答案1
我认为这是最简单的方法：语句在第一次出现时就被输入。
\documentclass{book}
\newtheorem{theorem}{Theorem}[chapter]
\ExplSyntaxOn
\NewDocumentEnvironment{restatethis}{m+b}
{% #1 (mandatory): a label
\group_begin:
\cs_gset:cpn {restatethis@#1}{ #2 }
\renewcommand{\thetheorem}{\ref{#1}}
\begin{theorem}#2\end{theorem}
\addtocounter{theorem}{-1}
\group_end:
}{}
\NewDocumentCommand{\restate}{m}
{
\begin{theorem}\label{#1}\use:c {restatethis@#1}\end{theorem}
}
\ExplSyntaxOff
\begin{document}
\frontmatter
\chapter{Introduction}
This is the introduction, where we have a theorem
\begin{restatethis}{main}
This is the main theorem in the thesis.
\end{restatethis}
\mainmatter
\chapter{Main result}
Here we prove our main theorem.
\restate{main}
\end{document}
定理的陈述位于主体中的替代解决方案。
\documentclass{book}
\newtheorem{theorem}{Theorem}[chapter]
\ExplSyntaxOn
\NewDocumentEnvironment{restatethis}{m+b}
{% #1 (mandatory): a label
\AddToHookNext{para/begin}{
\iow_shipout:cn { @auxout } {
\RESTATETHEOREM{#1}{#2}
}
}
\begin{theorem}\label{#1}#2\end{theorem}
}{}
\NewDocumentCommand{\RESTATETHEOREM}{mm}
{%
\cs_gset:cpn {RESTATETHIS@#1} {#2}%
}
\NewDocumentCommand{\restate}{m}
{
\group_begin:
\renewcommand{\thetheorem}{\ref{#1}}
\begin{theorem} \use:c {RESTATETHIS@#1} \end{theorem}
\addtocounter{theorem}{-1}
\group_end:
}
\ExplSyntaxOff
\begin{document}
\frontmatter
\chapter{Introduction}
This is the introduction, where we have a theorem
\restate{main}
\mainmatter
\chapter{Main result}
Here we prove our main theorem.
\begin{restatethis}{main}
This is the main theorem in the thesis.
\end{restatethis}
\end{document}
注：请参阅带有的原始代码的编辑历史\NewEnviron。
感谢 daleif 和 yo 提出的变更建议。
答案2
我一直在使用 @egreg 代码的稍作修改的版本，所以我想把它放在这里。它的设置与环境非常相似mathtools。restatable它可以与 amsthm、ntheorem 和 mathtools（当前版本）一起正常工作。
令人烦恼的是，如果您使用标准定理包将两个定理环境一起编号，则在编号推论时\newtheorem会定义\thecorollary但使用，因此重新定义根本不会改变编号。在这种情况下，我必须查看定义内部才能找出哪个宏拥有推论编号。包修复了这个缺陷，因此如果已加载，则只需重新定义即可。\thetheorem\thecorollary\corollarymathtools\thecorollary
\documentclass{article}
\usepackage{environ}
\newtheorem{thm}{Theorem}[section]
\newtheorem{cor}[thm]{Corollary}
\makeatletter
\long\def\@secondofthree#1#2#3{#2}
\long\def\@thirdoffour#1#2#3#4{#3}
% #1 -- theorem type
% #2 -- name
\NewEnviron{restatethis}[2]{%
\begin{#1}%
\BODY
% Do the write inside the body of the theorem environment because if I do it afterwards it messes
% up the spacing for some strange reason...
\protected@write\@auxout{}{%
\string\@restatetheorem{#1}{#2}{\csname the#1\endcsname}{\detokenize\expandafter{\BODY}}%
}%
\end{#1}%
}
% Figure out which macro to redefine to change the numbering.
% Easy if thmtools is loaded, otherwise we have to extract the name from some macro.
% This will break if some jerk loads thmtools and then ntheorem.
\@ifpackageloaded{thmtools}{%
% just use the name of the environment
\def\restatethm@getthmcountercsname#1{\def\thethmcsname{#1}}%
}{%
\@ifpackageloaded{ntheorem}{%
% extract the right macro from \mkheader@thmtype -> ???? \@thm{environmentname}{numberwithname}{thmname}
\def\restatethm@getthmcountercsname#1{%
\def\thethmcsname{\expandafter\expandafter\expandafter\restatethm@ntheorem@getthmcountercsname@helper\csname mkheader@#1\endcsname}}%
\def\restatethm@ntheorem@getthmcountercsname@helper#1\@thm#2#3#4{#3}
}{%
\@ifpackageloaded{amsthm}{%
% extract the right macro from \thmtype -> \@thm{????}{numberwithname}{thmname} (it's the third thing)
\def\restatethm@getthmcountercsname#1{\edef\thethmcsname{\expandafter\expandafter\expandafter\@thirdoffour\csname#1\endcsname}}%
}{%
% extract the right macro from \thmtype -> \@thm{numberwithname}{thmname} (it's the second thing)
\def\restatethm@getthmcountercsname#1{\edef\thethmcsname{\expandafter\expandafter\expandafter\@secondofthree\csname#1\endcsname}}%
}%
}%
}
% #1 -- environment type
% #2 -- name for restating
% #3 -- number
% #4 -- content
\newcommand{\@restatetheorem}[4]{%
\expandafter\gdef\csname restatethis@#2\endcsname{%
\begingroup
% First we have to set the numerical label to the right value.
\restatethm@getthmcountercsname{#1}
\expandafter\def\csname the\thethmcsname\endcsname{#3}%
% Print the theorem
\begin{#1}#4\end{#1}%
\endgroup
}%
}
\newcommand{\restate}[1]{\csname restatethis@#1\endcsname} % Just use the stored macro
\makeatother
\begin{document}
\section{Introduction}
This is the introduction, where we restate some theorems:
\restate{main}
\restate{acorollary}
\section{Main result}
Here we prove our main theorem.
\begin{restatethis}{thm}{main}
This is the main theorem in the thesis.
\end{restatethis}
\begin{restatethis}{cor}{acorollary}
This is a corollary.
\end{restatethis}
\end{document}