amsthm 定理環境後無縮排

Question

我使用 amsthm 包，並且不希望在定理環境之後開始的行縮排。我查閱了包包的手冊，它說定義一個新的定理樣式。我期望接下來的MWE能夠完成這個任務。

\documentclass[12pt,a4paper]{scrreprt}

\usepackage{amsthm}
\newtheoremstyle{abcd}% name
  {}%      Space above, empty = `usual value'
  {}%      Space below
  {\itshape}% Body font
  {}%         Indent amount (empty = no indent, \parindent = para indent)
  {\bfseries}% Thm head font
  {.}%        Punctuation after thm head
  {.5em}% Space after thm head: \newline = linebreak
  {}%         Thm head spec
\theoremstyle{abcd}

\newtheorem{defn}{Definition}
\begin{document}
\begin{defn}
Some defintion
\end{defn}
This sentence shouldn't be indented.
\end{document}

然而，我最終得到了這個

這就是我所期望的（在定理環境結束後立即使用 noindent 獲得）

Answer 1

\documentclass[12pt,a4paper]{scrreprt}
\usepackage{amsthm}
\usepackage{etoolbox}

\newtheorem{defn}{Definition}
\AfterEndEnvironment{defn}{\noindent\ignorespaces}

\begin{document}
\begin{defn}
Some definition.
\end{defn}
This sentence isn't indented.
\end{document}

然而這違背了直覺；定義（或任何其他類似定理的結構）之後的句子在邏輯上開始一個新段落，因此其第一行應被視為新段落的任何其他第一行。

Answer 2

您可以透過修補在單一定理類型的基礎上修復此問題\end<name>：

\documentclass{article}

\usepackage{etoolbox}
\usepackage{amsthm}

\newtheoremstyle{abcd}% name
  {}%      Space above, empty = `usual value'
  {}%      Space below
  {\itshape}% Body font
  {}%         Indent amount (empty = no indent, \parindent = para indent)
  {\bfseries}% Thm head font
  {.}%        Punctuation after thm head
  {.5em}% Space after thm head: \newline = linebreak
  {}%         Thm head spec

\theoremstyle{abcd}
\newtheorem{defn}{Definition}

\makeatletter
\patchcmd{\enddefn}{\@endpefalse}{}{}{}
\makeatother


\begin{document}

\begin{defn}
Some definition
\end{defn}
This sentence shouldn't be indented.

\begin{defn}
Some definition
\end{defn}

This sentence should be indented.

\end{document}

風格選擇沒有影響。

為了獲得相同的行為全部定理環境，改變 的定義\@endtheorem。

\documentclass{article}

\usepackage{amsthm}

\makeatletter
\def\@endtheorem{\endtrivlist}
\makeatother

\newtheoremstyle{abcd}% name
  {}%      Space above, empty = `usual value'
  {}%      Space below
  {\itshape}% Body font
  {}%         Indent amount (empty = no indent, \parindent = para indent)
  {\bfseries}% Thm head font
  {.}%        Punctuation after thm head
  {.5em}% Space after thm head: \newline = linebreak
  {}%         Thm head spec

\theoremstyle{abcd}
\newtheorem{defn}{Definition}

\begin{document}

\begin{defn}
Some definition
\end{defn}
This sentence shouldn't be indented.

\begin{defn}
Some definition
\end{defn}

This sentence should be indented.

\end{document}

另一個例子表明，當兩個定理環境相互跟隨時，這不會添加不必要的空間。

\documentclass{scrbook}

\usepackage{amsthm}
\makeatletter
\def\@endtheorem{\endtrivlist}
\makeatother

\theoremstyle{plain}
\newtheorem{thm}{Theorem}[chapter]
\newtheorem*{thm*}{Theorem}

\begin{document}

\chapter{Chapter}

\section{Section}

Some text. Some text. Some text. Some text. Some text. Some text. Some text. Some text. Some text. Some text. 

\begin{thm}
    Theorem. Theorem. Theorem. Theorem. Theorem. Theorem. Theorem. Theorem. Theorem. Theorem. 
\end{thm}
No indentation. Some text. Some text. Some text. Some text. Some text. Some text. Some text. Some text. Some text. Some text. 

\begin{thm}
    Theorem. Theorem. Theorem. Theorem. Theorem. Theorem. Theorem. Theorem. Theorem. Theorem. 
\end{thm}

\begin{thm}
    Theorem. Theorem. Theorem. Theorem. Theorem. Theorem. Theorem. Theorem. Theorem. Theorem. 
\end{thm}

Indentation. Some text. Some text. Some text. Some text. Some text. Some text. Some text. Some text. Some text. Some text. 

\end{document}