如何为定理计数器设置自定义分隔符？例如在
章节、节和编号用点。我怎样才能将这些点改为其他符号？例如，我怎样才能将第一个点改为破折号，将第二个点改为逗号？
这是从中提取的代码本网站产生了上面的图片：
\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage[english]{babel}
\newtheorem{theorem}{Theorem}[section]
\newtheorem{corollary}{Corollary}[theorem]
\newtheorem{lemma}[theorem]{Lemma}
\begin{document}
\section{Introduction}
Theorems can easily be defined
\begin{theorem}
Let $f$ be a function whose derivative exists in every point, then $f$ is
a continuous function.
\end{theorem}
\begin{theorem}[Pythagorean theorem]
\label{pythagorean}
This is a theorema about right triangles and can be summarised in the next
equation
\[ x^2 + y^2 = z^2 \]
\end{theorem}
And a consequence of theorem \ref{pythagorean} is the statement in the next
corollary.
\begin{corollary}
There's no right rectangle whose sides measure 3cm, 4cm, and 6cm.
\end{corollary}
You can reference theorems such as \ref{pythagorean} when a label is assigned.
\begin{lemma}
Given two line segments whose lengths are $a$ and $b$ respectively there is a
real number $r$ such that $b=ra$.
\end{lemma}
\end{document}
答案1
改变计数器的表示形式：
\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage[english]{babel}
\usepackage{siunitx}
\newtheorem{theorem}{Theorem}[section]
\renewcommand{\thetheorem}{\thesection--\arabic{theorem}}
\newtheorem{lemma}[theorem]{Lemma}
\newtheorem{corollary}{Corollary}[theorem]
\renewcommand{\thecorollary}{\thetheorem, \arabic{corollary}}
\begin{document}
\section{Introduction}
Theorems can easily be defined
\begin{theorem}
Let $f$ be a function whose derivative exists in every point, then $f$ is
a continuous function.
\end{theorem}
\begin{theorem}[Pythagorean theorem]
\label{pythagorean}
This is a theorema about right triangles and can be summarised in the next
equation
\[ x^2 + y^2 = z^2 \]
\end{theorem}
And a consequence of theorem \ref{pythagorean} is the statement in the next
corollary.
\begin{corollary}
There's no right rectangle whose sides measure \SI{3}{cm}, \SI{4}{cm}, and \SI{6}{cm}.
\end{corollary}
You can reference theorems such as \ref{pythagorean} when a label is assigned.
\begin{lemma}
Given two line segments whose lengths are $a$ and $b$ respectively there is a
real number $r$ such that $b=ra$.
\end{lemma}
\end{document}
