推论远离其定理

Question

我正在使用amsthm。thmtools当推论紧跟其定理时，编号会自动输出为

定理 n

推论 1

命题 n+1

但是，如果我在其中插入其他编号环境会怎样？我如何获得：

定理 n

命题 n+1

定理 n+2

推论 1

命题 n+3

Answer 1

我建议定义corollary一个可选参数。如果为空或缺失，则假设推论指的是最后陈述的定理（当然是命题）。

如果推论是分离的，则需要将其添加\label到父定理并使用标签作为推论的可选参数。

\documentclass{article}
\usepackage{amsmath}

\newtheorem{theorem}{Theorem}
\newtheorem{proposition}[theorem]{Proposition}

\newtheorem{corollaryinner}{Corollary}[theorem] % just the internal version
\newenvironment{corollary}[1][]
 {% #1 is the cross reference label
  \if\relax\detokenize{#1}\relax
    % we have a corollary directly following a theorem, do nothing special
  \else
    \ifcsname #1-used\endcsname
      \expandafter\xdef\csname #1-used\endcsname{\the\numexpr\csname #1-used\endcsname+1}%
    \else
      \expandafter\gdef\csname #1-used\endcsname{1}%
    \fi
    \renewcommand{\thecorollaryinner}{\ref{#1}.\csname #1-used\endcsname}%
  \fi
  \corollaryinner
 }
 {\endcorollaryinner}

\begin{document}

\section{Corollary follows directly}

\begin{theorem}
A theorem
\end{theorem}

\begin{corollary}
A corollary
\end{corollary}

\begin{corollary}
Another corollary
\end{corollary}

\begin{proposition}
A proposition
\end{proposition}

\section{Corollary is detached}

\begin{theorem}\label{theorem}
A theorem
\end{theorem}

\begin{proposition}
A proposition
\end{proposition}

\begin{corollary}[theorem]
A corollary
\end{corollary}

\begin{proposition}
Another proposition
\end{proposition}

\begin{corollary}[theorem]
Another corollary
\end{corollary}

\end{document}

相同的使用expl3功能：我维护一个带有交叉引用的属性列表，目的与以前相同，即跟踪已经使用的引用。

\documentclass{article}
\usepackage{amsmath}

\newtheorem{theorem}{Theorem}
\newtheorem{proposition}[theorem]{Proposition}

\newtheorem{corollaryinner}{Corollary}[theorem] % just the internal version

\ExplSyntaxOn

\NewDocumentEnvironment{corollary}{o}
 {
  \IfValueT { #1 }
   {
    \giobrach_corollary_setup:n { #1 }
   }
  \corollaryinner
 }
 { \endcorollaryinner }

\prop_new:N \g_giobrach_corollary_prop

\cs_new_protected:Nn \giobrach_corollary_setup:n
 {
  \prop_gput:Nnx \g_giobrach_corollary_prop { #1 }
   {
    \int_eval:n { \prop_item:Nn \g_giobrach_corollary_prop { #1 } + 1 }
   }
  \cs_set:Npn \thecorollaryinner {\ref {#1}.\prop_item:Nn \g_giobrach_corollary_prop { #1 }}
 }

\ExplSyntaxOff

\begin{document}

\section{Corollary follows directly}

\begin{theorem}
A theorem
\end{theorem}

\begin{corollary}
A corollary
\end{corollary}

\begin{corollary}
Another corollary
\end{corollary}

\begin{proposition}
A proposition
\end{proposition}

\section{Corollary is detached}

\begin{theorem}\label{theorem}
A theorem
\end{theorem}

\begin{proposition}
A proposition
\end{proposition}

\begin{corollary}[theorem]
A corollary
\end{corollary}

\begin{proposition}
Another proposition
\end{proposition}

\begin{corollary}[theorem]
Another corollary
\end{corollary}

\end{document}

Answer 2

这是@egreg 的答案的修改版本。它使用 <...> 作为要遵循的定理的标签，同时保留[...]为描述文本。因此，正常的推论仍然看起来像

\begin{corollary}[description]
Another corollary
\end{corollary}

而定理中编号的推论则\label{thm:1}看起来像

\begin{corollary}<thm:1>[description]
A corollary
\end{corollary}

\documentclass{article}
\usepackage{amsmath}

\newtheorem{theorem}{Theorem}
\newtheorem{proposition}[theorem]{Proposition}

\newtheorem{corollaryinner}{Corollary}[theorem] % just the internal version
\NewDocumentEnvironment{corollary}{D<>{}}
 {% #1 is the cross reference label
  \if\relax\detokenize{#1}\relax
    % we have a corollary directly following a theorem, do nothing special
  \else
    \ifcsname #1-used\endcsname
      \expandafter\xdef\csname #1-used\endcsname{\the\numexpr\csname #1-used\endcsname+1}%
    \else
      \expandafter\gdef\csname #1-used\endcsname{1}%
    \fi
    \renewcommand{\thecorollaryinner}{\ref{#1}.\csname #1-used\endcsname}%
  \fi
  \corollaryinner
 }
 {\endcorollaryinner}

\begin{document}

\section{Corollary follows directly}

\begin{theorem}
A theorem
\end{theorem}

\begin{corollary}[description]
A corollary
\end{corollary}

\begin{corollary}[description]
Another corollary
\end{corollary}

\begin{proposition}
A proposition
\end{proposition}

\section{Corollary is detached}

\begin{theorem}\label{theorem}
A theorem
\end{theorem}

\begin{proposition}
A proposition
\end{proposition}

\begin{theorem}
An unrelated theorem
\end{theorem}

\begin{corollary}<theorem>[description]
A corollary
\end{corollary}

\begin{proposition}
Another proposition
\end{proposition}

\begin{corollary}<theorem>[description]
Another corollary
\end{corollary}

\end{document}

---

旧答案： 您可以存储计数器的值theorem并对其中的推论进行编号。

\documentclass{article}
\usepackage{amsthm}
\usepackage{thmtools}
\declaretheorem{theorem}
\declaretheorem[sibling=theorem]{proposition}
\newcounter{theoremrecord}
\let\theoremOriginal=\theorem
\renewcommand{\theorem}{\theoremOriginal\setcounter{theoremrecord}{\value{theorem}}}
\declaretheorem[numberwithin=theoremrecord]{corollary}
\begin{document}
\begin{theorem}
    ...
\end{theorem}
\begin{proposition}
    ...
\end{proposition}
\begin{corollary}
    ...
\end{corollary}
\end{document}