我想用粗体字体排版一个涉及极限的表达式。我的代码只将部分字符排版为粗体。不过，那些粗体字母不是斜体。
\documentclass[10pt]{amsart}
\usepackage{mathtools}
\begin{document}
\noindent
\begin{minipage}{5.75in}
{\em A sequence $(a_{n})_{\scriptscriptstyle{n=1}}^{\scriptscriptstyle{\infty}}$ \textbf{diverges to \boldmath$\infty$\unboldmath} if, and only if, for every $M > 0$, there is a big enough positive integer $N$ so that for every integer $n \geq N$, $a_{n} > M$.}
{\boldmath
\begin{equation*}
\mathbf{\displaystyle{\lim_{n\to\infty} a_{n} = \infty}}
\end{equation*}
}
{\em denotes the condition that $(a_{n})_{\scriptscriptstyle{n=1}}^{\scriptscriptstyle{\infty}}$ diverges to $\infty$.}
\end{minipage}
\end{document}
答案1
如果您只想要加粗方程的一部分，请使用包\bm。对于整个方程，我定义了一个，boldeqn*后面\boldmath跟着一个equation*环境：
\documentclass{amsart}
\usepackage{mathtools}
\usepackage{bm}
\newenvironment{boldeqn*}{\boldmath\begin{equation*}}{\end{equation*}\ignorespacesafterend}
\begin{document}
\noindent A sequence $(a_{n})_{n=1}^{\infty}$ diverges to $\infty$ if, and only if, for every $M > 0$, there is a big enough positive integer $N$ so that for every integer $n \geq N$, $a_{n} > M$.
\begin{boldeqn*}
\lim_{n\to\infty} a_{n} = \infty
\end{boldeqn*}
\begin{equation*}
\bm{\lim_{n\to\infty} a_{n} = \infty} \qquad \lim_{n\to\infty}b_{n} = 0
\end{equation*}
\end{document}
