我如何按层次对子定理进行编号？

Question

我想创建两个层次的定理。目标是得到如下的东西：

Research Question 1: bla bla
Research Question 2: bla bla

然后在文章的另一部分，我想做这样的事情：

Research Question 1.1 bla bla
Research Question 1.2 bla bla

Research Question 2.1 bla bla
Research Question 2.2 bla bla

我使用了以下代码：

\newtheorem{researchquestion}{Research Question}

\makeatletter
\newenvironment{subresearchquestion}[1]{%
  \def\subtheoremcounter{#1}%
  \refstepcounter{#1}%
  \protected@edef\theparentnumber{\csname the#1\endcsname}%
  \setcounter{parentnumber}{\value{#1}}%
  \setcounter{#1}{0}%
  \expandafter\def\csname the#1\endcsname{\theparentnumber.\Alph{#1}}%
  \ignorespaces
}{%
  \setcounter{\subtheoremcounter}{\value{parentnumber}}%
  \ignorespacesafterend
}
\makeatother
\newcounter{parentnumber}

然而，结果并不完全是应该的样子：研究问题 1：bla bla 研究问题 2：bla bla

然后在文章的另一部分，我想做这样的事情：

Research Question 3.1 bla bla
Research Question 3.2 bla bla

Research Question 4.1 bla bla
Research Question 4.2 bla bla

我怎样才能实现子定理真的是子定理？我尝试了这种方法：如何按层次对子定理进行编号？但问题是定理编号受章节编号影响。我希望这两件事是独立的。

Answer 1

也可以看看从定理编号中删除章节编号

\documentclass{article}   

\newtheorem{theorem}{Theorem}[section]
\newtheorem{subtheorem}{Sub-Theorem}[theorem]

\renewcommand{\thetheorem}{\arabic{theorem}}
\renewcommand{\thesubtheorem}{\arabic{theorem}.\arabic{subtheorem}}

\begin{document}
\section{Introduction}

\begin{theorem} 
 Yada yada yada. 
\end{theorem}   

\begin{subtheorem}   
  Yada yada yada.
\end{subtheorem}

\begin{subtheorem}   
  Yada yada yada.
\end{subtheorem}

\begin{theorem} 
 Yada yada yada. 
\end{theorem}   

\begin{subtheorem}   
  Yada yada yada.
\end{subtheorem}

\begin{subtheorem}   
  Yada yada yada.
\end{subtheorem}

\end{document}