答案1
使用aligned
、 或multlined
。最好,对于单词或首字母缩略词的下标,使用命令\text
,以获得正确的字母间距:
\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{mathtools,cases}
%%%%%
\begin{document}
\begin{numcases}{\begin{aligned}\mathcal{F}( & \mathcal{B}(\mathcal{P}_\text{err})[n],\\&\mathcal{B}(\mathcal{P}_\text{cor})[n^\prime]) \end{aligned}= }
XXXXXXX \\ YYYYYYYY \\ ZZZZZZZ
\end{numcases}
\begin{numcases}{\begin{multlined}\mathcal{F}(\mathcal{B}(\mathcal{P}_\text{err})[n],\\\mathcal{B}(\mathcal{P}_\text{cor})[n^\prime]) \end{multlined}= }
XXXXXXX \\ YYYYYYYY \\ ZZZZZZZ
\end{numcases}
\end{document}