帶子定理的定理編號，不含節號

Question

我正在使用IEEEtran類別和\usepackage{amsthm}.如何為定理設定一個獨立於各部分的計數器？假設我的第一個定理有三個部分，第二個定理有兩個部分。我怎樣才能生成？

定理1.1

定理1.2

定理1.3

定理2.1

定理2.2

Answer 1

我建議您建立一個專用的計數器變數（例如mythmcounter，稱為），並建立一個專用的類似定理的環境（例如mythm，稱為），其編號從屬於 的值mythmcounter。\stepcounter{mythmcounter}根據需要運行指令。

\documentclass{IEEEtran}
\usepackage{amsthm}

\newcounter{mythmcounter}
\newtheorem{mythm}{Theorem}[mythmcounter]

\begin{document}

\stepcounter{mythmcounter}
\begin{mythm} abc \end{mythm}
\begin{mythm} def \end{mythm}

\stepcounter{mythmcounter}
\begin{mythm} ghi \end{mythm}
\begin{mythm} jkl \end{mythm}
\begin{mythm} mno \end{mythm}

\end{document}

Answer 2

我不確定我是否完全理解了這個問題，但應該subtheorems有一個定理和一個子定理數。最簡單的方法是定義一個subtheorem使用theorem計數器作為驅動程式計數器的新環境。

第一次出現這樣的子定理需要 a \setcounter{theorem}{1}，下一個（如果直接跟隨子定理）需要 a\stepcounter{theorem}來強制重置子定理計數器。

\documentclass{IEEEtran}


\usepackage{amsthm}

\newtheorem{theorem}{Theorem}

\newtheorem{subtheorem}{Subtheorem}[theorem]

\begin{document}

\section{Foo section}
\setcounter{theorem}{1}
\begin{subtheorem}{Part one}
\end{subtheorem}


\begin{subtheorem}{Part two}
\end{subtheorem}


\begin{subtheorem}{Part three}
\end{subtheorem}

\stepcounter{theorem}
\begin{subtheorem}{Part one}
\end{subtheorem}


\begin{subtheorem}{Part two}
\end{subtheorem}


\end{document}

Answer 3

借用subequations自amsmath：

\documentclass{IEEEtran}
\usepackage{amsthm}

\newtheorem{theorem}{Theorem}

\makeatletter
\newcounter{parenttheorem}
\newenvironment{subtheorems}{%
  \refstepcounter{theorem}%
  \protected@edef\theparenttheorem{\thetheorem}%
  \setcounter{parenttheorem}{\value{theorem}}%
  \setcounter{theorem}{0}%
  \def\thetheorem{\theparenttheorem.\arabic{theorem}}%
  \ignorespaces
}{%
  \setcounter{theorem}{\value{parenttheorem}}%
  \ignorespacesafterend
}
\makeatother

\begin{document}

\begin{theorem}
This has no parts.
\end{theorem}

\begin{subtheorems}
\begin{theorem}
First part 2
\end{theorem}

\begin{theorem}
Second part 2
\end{theorem}
\end{subtheorems}

\begin{theorem}
This has no parts.
\end{theorem}

\begin{subtheorems}
\begin{theorem}
First part 4
\end{theorem}

\begin{theorem}
Second part 4
\end{theorem}

\begin{theorem}
Third part 4
\end{theorem}
\end{subtheorems}

\begin{theorem}
This has no parts.
\end{theorem}

\end{document}