我想在主定理体内写几个定理。具体来说，我想写类似下面的内容：
我尝试使用命令 \newtheorem 创建主定理，然后在其中使用命令 \begin{theorem}，但它没有达到目的。我希望像这样具体一点：
谢谢您的帮助！！
答案1
以下是使用 的实现enumitem。
\documentclass{article}
\usepackage{amsmath}
\usepackage{amsthm}
\usepackage{enumitem}
\usepackage{lipsum}
\newtheorem{theorem}{Theorem}[section]
\newtheorem*{main}{Main Theorem}
\newenvironment{subtheorems}
{\itemize[
nosep,font=\normalfont\bfseries,
leftmargin=3em,itemindent=-1em,align=left]}
{\enditemize}
\begin{document}
\section{Introduction}
\lipsum[2]
\begin{main}
We obtain the following bijective correspondences.
\begin{subtheorems}
\item[$\mathbf{C}^*$-case (Theorem \ref{C*case}):]
Let $\Gamma$ be a discrete group \lipsum*[3]
\item[$\mathbf{W}^*$-case (Theorem \ref{W*case}):]
Let $\Gamma$ be a countable group \lipsum[4]
\end{subtheorems}
\end{main}
\lipsum
\setcounter{section}{2}\setcounter{theorem}{2}
\begin{theorem}\label{C*case}
Text
\end{theorem}
\setcounter{section}{3}\setcounter{theorem}{5}
\begin{theorem}\label{W*case}
Text
\end{theorem}
\end{document}
一种不同的实现，具有编号的子定理。
\documentclass{article}
\usepackage{amsmath}
\usepackage{amsthm}
\usepackage{enumitem}
\usepackage{lipsum}
\newtheorem{theorem}{Theorem}[section]
\newtheorem*{main}{Main Theorem}
\newenvironment{subtheorems}
{\enumerate[
label=Theorem \Alph*\protect\thissubtheorem,
ref=\Alph*,
font=\normalfont\bfseries,
leftmargin=0pt,itemindent=!,
align=left,
]}
{\endenumerate}
\newcommand{\thissubtheorem}{}
\newcommand{\subtheorem}[1][]{%
\if\relax\detokenize{#1}\relax
\def\thissubtheorem{}%
\else
\def\thissubtheorem{ (#1)}%
\fi
\item
}
\begin{document}
\section{Introduction}
\lipsum[2]
\begin{main}
We obtain the following bijective correspondences.
\begin{subtheorems}
\subtheorem[$\mathbf{C}^*$-case]\label{C*case}
Let $\Gamma$ be a discrete group \lipsum*[3]
\subtheorem[$\mathbf{W}^*$-case]\label{W*case}
Let $\Gamma$ be a countable group \lipsum[4]
\end{subtheorems}
\end{main}
Theorem~\ref{C*case} and theorem~\ref{W*case} are important.
\end{document}
