定理和定义名称在页边

Question

我想让定理名称出现在页边空白处。我尝试使用页边注释来实现这一点，但无法实现。

这是我正在尝试做的事情的图片。上面一行是定理环境默认的工作方式，下面是我想要的。

这是我尝试做的事情，尽管我必须承认我不太了解如何做这样的事情

 \newenivorment{margintheorem}[#2]{
 \begin{theorem}[\marginnote{#2}]

 \end{theorem}
 }

Answer 1

您可以间接定义theorem环境：

\documentclass{article}
\usepackage{amsthm,marginnote,xparse}

\newtheorem{theoreminner}{Theorem}
\NewDocumentEnvironment{theorem}{o}
 {\theoreminner\IfValueT{#1}{\marginnote{\normalfont\footnotesize#1}}}
 {\endtheoreminner}

\reversemarginpar

\begin{document}

\begin{theorem}
This theorem has no attribution.
\end{theorem}

\begin{theorem}[theorem name]
This theorem has a name.
\end{theorem}

\end{document}

Answer 2

您的问题缺少一些重要细节，特别是您没有说明是否使用特定包来定义“类定理”环境。我假设您使用的是amsthm。

以下解决方案直接侵入amsthm命令的定义\@begintheorem，因此可自动应用于所有类型的“类定理”环境（命题、引理、定义……）。它基于\marginparLaTeX 内核中命令的使用：这使事情变得有点复杂，因为必须“在外部段落模式下”发出此命令。事实上，我编写代码的目的正是要表明基于原始命令的解决方案\marginpar是可能的。

% My standard header for TeX.SX answers:
\documentclass[a4paper]{article} % To avoid confusion, let us explicitly 
                                 % declare the paper format.

\usepackage[T1]{fontenc}         % Not always necessary, but recommended.
% End of standard header.  What follows pertains to the problem at hand.

% \usepackage{amsmath} % not essential, but you probably want it too
\usepackage{amsthm}
\usepackage{etoolbox} % for "\patchcmd"/"\pretocmd"



%%%%%%%% BEGIN WIZARDRY %%%%%%%%

\makeatletter

\wlog{****************************************}
\patchcmd{\@begintheorem}{% search for:
    \@ifempty{#3}{\let\thmnote\@gobble}{\let\thmnote\@iden}%
    \thm@swap\swappedhead\thmhead{#1}{#2}{#3}%
}{% replace with:
    \let\thmnote\@gobble
    \thm@swap\swappedhead\thmhead{#1}{#2}{}%
}{% execute if succeeded:
    \wlog{>>> 1st patch succeeded.}
}{% execute if failed:
    \wlog{>>> 1st patch FAILED!}
}
\pretocmd{\@begintheorem}{% prepended code:
    \@ifnotempty{#3}{\def\@thm@marginal@note@text{#3}}%
}{% execute if succeeded:
    \wlog{>>> 2nd patch succeeded.}
}{% execute if failed:
    \wlog{>>> 2nd patch FAILED!}
}
\wlog{****************************************}

\newcommand*\@thm@marginal@note@text{}
\newcommand*\@thm@marginal@note@helper{%
    \begingroup \setbox\z@ \lastbox \endgroup
    \marginnote{\@thm@marginal@note@text}%
}
\dth@everypar = \expandafter {%
    \expandafter \@thm@marginal@note@helper
    \the \dth@everypar
}

\makeatother

%%%%%%%%  END WIZARDRY  %%%%%%%%



\newcommand*{\marginnote}[1]{%
    \marginpar
        [\footnotesize\raggedleft  #1]%
        {\footnotesize\raggedright #1}%
}
\reversemarginpar % ?

\newtheorem{theorem}{Theorem}
\newtheorem{lemma}  {Lemma}
\theoremstyle{definition}
\newtheorem{defin}{Definition}



\begin{document}

This text comes before the first definition.

\begin{defin}[Important definition]
    A definition is \textbf{important} if and only if it is not
    unimportant.
\end{defin}

And, of course:

\begin{defin}
    An \textbf{unimportant} definition is one that is not important.
\end{defin}

Now a theorem:

\begin{theorem}[Important Theorem]
    All theorems are important, but some theorems are more important 
    than others.
\end{theorem}

The proof rests on the following

\begin{lemma}[Important lemma]
    Not all theorems (or lemmas) are equally important.
\end{lemma}

An unimportant theorem:

\begin{theorem}
    Blah blah blah\ldots
\end{theorem}

And an unimportant lemma:

\begin{lemma}
    Blah blah blah\ldots
\end{lemma}

Here is a little more text.

\end{document}

请注意老式的“复古”代码及其使用\expandafter... ;-)

输出：