如果定理中的“定理”一词出现在另一个环境中，则不会加粗

Question

我正在输入问题集的解决方案。我定义了一个theorem和solution环境，如以下文档所示。

\documentclass{article}

\usepackage{amsthm} 
\theoremstyle{plain}
\newtheorem{theorem}{Theorem}
\theoremstyle{definition}
\newtheorem{problem}{Problem}
\theoremstyle{remark}
\newtheorem*{solution}{Solution}

\begin{document}
\begin{theorem}
 The word ``theorem'' at the beginning of a theorem is bold, unless it appears inside a solution.
\end{theorem}

\begin{problem}
 What is $2+2$?
\end{problem}

\begin{solution}
 We use the following theorem.
\begin{theorem} Numbers can be added.\end{theorem} 
The result is therefore $2+2=4$.
\end{solution}

\end{document}

对于定理外部解决方案中，“定理”一词正确显示为粗体。然而，里面解决方案环境，定理环境的标题为斜体，与解决方案环境的风格相匹配。

我如何才能使解决方案中的定理正确地以粗体显示？

Answer 1

这是 的一个缺点amsthm。您可以使用以下方法解决此问题thmtools：

\documentclass{article}

\usepackage{amsthm,thmtools}

\declaretheoremstyle[
  headfont=\bfseries,
  bodyfont=\itshape,
]{myplain}
\declaretheoremstyle[
  headfont=\bfseries,
  bodyfont=\normalfont,
]{mydefinition}
\declaretheoremstyle[
  headfont=\itshape,
  bodyfont=\normalfont,
]{myremark}

\declaretheorem[
  style=myplain,
  name=Theorem,
]{theorem}
\declaretheorem[
  style=mydefinition,
  name=Problem,
]{problem}
\declaretheorem[
  style=myremark,
  unnumbered,
  name=Solution,
]{solution}

\begin{document}

\begin{theorem}
 The word ``theorem'' at the beginning of a theorem is bold, unless it appears inside a solution.
\end{theorem}

\begin{problem}
 What is $2+2$?
\end{problem}

\begin{solution}
 We use the following theorem.
\begin{theorem} Numbers can be added.\end{theorem} 
\begin{problem} Numbers can be added.\end{problem} 
The result is therefore $2+2=4$.
\end{solution}

\end{document}