如何获得分数环境数

Question

出于某种搞笑，我想提出一个带有分数的定理。如果我必须具体给出数字，那就完全没问题。

然而，我确实不是想要为此定义一个新的环境，因为我想重用该定理的样式，并且希望在我改变该定理的布局时它也随之改变。

我尝试了类似的方法\renewcommand{\thetheorem}{9$\fraction{3}{4}}，但这不起作用，因为\refstepcounter（由定理自动调用）只是覆盖了它，而我不知道如何防止这种情况发生。

我知道这有点傻而且没有什么实际用途，但这仍然是我想做的一件有趣的事。

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编辑：

我用它thmtools来生成我的定理环境，但这似乎不是一个问题，它仍然有效。

但是，我的问题似乎是包cleveref和我希望它适用于与定理共享计数器的定义这一事实的结合。如果我cleveref只使用定理，一切都很好。如果我不使用cleveref，下面的代码也适用于定义，与定理共享计数器。

但是，当我同时使用它们时，我就会得到编译错误，并且定义会变得混乱。警告似乎也帮不上什么忙。

下面是一个 MWE（注释掉时有效cleveref，但在使用包时失败）：

\documentclass{article}

\usepackage{amsmath,amsthm}
%\usepackage{cleveref}
\usepackage{hyperref}

\newtheorem{theorem}{Theorem}
\newtheorem{definition}[theorem]{Definition}

\begin{document}
See Theorem~\ref{thm:first}, Theorem~\ref{thm:second} or Theorem~\ref{thm:third} or Definition~\ref{def:third}.

\begin{theorem}
  First theorem.\label{thm:first}
\end{theorem}

\begin{theorem}[Second]
  Second theorem.\label{thm:second}
\end{theorem}

\begingroup
\renewcommand{\refstepcounter}[1]{}% Remove functionality of \refstepcounter
%\stepcounter{theorem}% Step default theorem counter % Commented out because using hyperref
\renewcommand{\thetheorem}{\arabic{theorem}$\mathbf{\tfrac{3}{4}}$}% Setup printing of theorem counter
\begin{theorem}
  Third theorem.%
  \makeatletter
  \renewcommand{\@currentlabel}{\arabic{theorem}$\tfrac{3}{4}$}% Update theorem reference
  \makeatother
  \label{thm:third}% Capture reference in \label
\end{theorem}
\endgroup

\begingroup
\renewcommand{\refstepcounter}[1]{}% Remove functionality of \refstepcounter
%\stepcounter{theorem}% Step default theorem counter % Commented out because using hyperref
\renewcommand{\thetheorem}{\arabic{theorem}$\mathbf{\tfrac{3}{4}}$}% Setup printing of theorem counter
\begin{definition}
  Third theorem.%
  \makeatletter
  \renewcommand{\@currentlabel}{\arabic{theorem}$\tfrac{3}{4}$}% Update theorem reference
  \makeatother
  \label{def:third}% Capture reference in \label
\end{definition}
\endgroup

\begin{theorem}
  Fifth theorem.
\end{theorem}

\end{document}

Answer 1

您需要做一些手动的工作，但这是可行的：

\documentclass{article}

\usepackage{amsmath,amsthm}

\newtheorem{theorem}{Theorem}

\begin{document}

See Theorem~\ref{thm:first}, Theorem~\ref{thm:second} or Theorem~\ref{thm:third}.

\begin{theorem}
  First theorem.\label{thm:first}
\end{theorem}

\begin{theorem}[Second]
  Second theorem.\label{thm:second}
\end{theorem}

\begingroup
\renewcommand{\refstepcounter}[1]{}% Remove functionality of \refstepcounter
\stepcounter{theorem}% Step default theorem counter
\renewcommand{\thetheorem}{\arabic{theorem}$\mathbf{\tfrac{3}{4}}$}% Setup printing of theorem counter
\begin{theorem}
  Third theorem.%
  \makeatletter
  \renewcommand{\@currentlabel}{\arabic{theorem}$\tfrac{3}{4}$}% Update theorem reference
  \makeatother
  \label{thm:third}% Capture reference in \label
\end{theorem}
\endgroup

\begin{theorem}
  Fourth theorem.
\end{theorem}

\end{document}

\stepcounter{theorem}如果你正在使用，删除它似乎就足够了hyperref也一样。

Answer 2

您可以使用\tag来自 的命令amsmath。

\documentclass{article}
\usepackage{amsmath}
\begin{document}
\begin{equation}
a = b + c
\tag{9$\frac{3}{4}$}
\label{eq:ntf}
\end{equation}

Look at Equation \ref{eq:ntf} to find $a$.
\end{document}

Answer 3

假设“gag”以最后一个定理数作为主数，那就更容易了……

只需注意hyperref并指定一个唯一的锚点名称即可。我们还需要说服amsthm在定理头中使用粗体数学。请注意cleveref应该在之后hyperref。

\documentclass{article}

\usepackage{amsmath,amsthm}
\usepackage{hyperref}
\usepackage{cleveref}

\newtheorem{theorem}{Theorem}
\newtheorem{definition}[theorem]{Definition}

\newcounter{gag}
\makeatletter
\newenvironment{gag}[1]{%
  \let\savedthetheorem\thetheorem
  \thm@headfont{\bfseries\boldmath}%
  \stepcounter{gag}%
  \renewcommand{\thetheorem}{\savedthetheorem#1}%
  \renewcommand{\theHtheorem}{gag\thegag}%
  \addtocounter{theorem}{-1}\ignorespaces
}{\ignorespacesafterend}
\makeatother

\begin{document}

See \Cref{thm:first}, \Cref{thm:second} or 
\Cref{thm:third} or \Cref{def:third}.

\begin{theorem}
First theorem.\label{thm:first}
\end{theorem}

\begin{theorem}[Second]
Second theorem.\label{thm:second}
\end{theorem}

\begin{gag}{$\frac{3}{4}$}
\begin{theorem}\label{thm:third}
Third theorem.
\end{theorem}
\end{gag}

\begin{gag}{$\frac{3}{4}$}
\begin{definition}\label{def:third}
Definition.
\end{definition}
\end{gag}

\begin{theorem}
Fifth theorem.
\end{theorem}

\end{document}