答案1
输出使用mathtools
' 可扩展\xmapsto
:
\documentclass{article}
\usepackage{mathtools}
\DeclareMathOperator{\Hom}{Hom}
\usepackage{lipsum}
\begin{document}
\lipsum[1]
\[
\varphi
\xmapsto{\makebox[.35\linewidth]{\raisebox{.5\baselineskip}{$
\Hom_R(M \otimes_R N, P) \cong
\{ \text{Bilinear maps $M \times N$ to $P$} \}
$}}}
\varphi b.
\]
\lipsum[2]
\end{document}
答案2
以下是一种方法:
\documentclass{article}
\usepackage[showframe]{geometry} %
\usepackage{mathtools}
\DeclareMathOperator{\Hom}{Hom}
\begin{document}
\begin{alignat*}{2}
\Hom(M & \otimes_R N, P)\simeq \bigl\{\text{Bilinear maps }M & & \times N\enspace \text{to}\enspace P\bigr\}\\
& \;\varphi \mathrel{\mathrlap{\xmapsto{\hspace{11.65em}}}} & & \varphi b
\end{alignat*}
\end{document}