答案1
只是为了好玩,我想我会展示我能想到的所有实现此效果的方法。有趣的是,使用 amsthm 或 enumerate 太费力了。
\documentclass{article}
\usepackage{amsmath}
\usepackage{blindtext}
\usepackage{paracol}
\newcounter{theorem}
\renewcommand{\thetheorem}{\thesection-\arabic{theorem}}
\setcounter{section}{10}
\globalcounter{theorem}% for paracol
\begin{document}
\begin{itemize}
\item[\stepcounter{theorem}\thetheorem] \blindtext
\end{itemize}
\hangindent=2.5em
\noindent\hbox to 2.5em{\stepcounter{theorem}\thetheorem\hfill}\blindtext
\medskip
\noindent\makebox[2.5em][l]{\stepcounter{theorem}\thetheorem}%
\parbox[t]{\dimexpr \textwidth-2.5em}{\blindtext}% will not break across tables
\setcolumnwidth{\dimexpr 2.5em-\columnsep}%
\medskip
\begin{paracol}{2}
\parindent=0pt
\stepcounter{theorem}\thetheorem
\switchcolumn
\blindtext
\end{paracol}
\end{document}