我怎样才能将条件线放在方程组内的方程之间？

Question

我想这样将条件放入方程组中，当前脚本不起作用：

$ 
y_v=\left\{
\begin{aligned}
1,$ if v was received and decodable, $ & \forall v \in V \\
0, $otherwise $
\end{aligned}
\right.
$

知道如何正确定位吗？

Answer 1

\documentclass{article}
\usepackage{mathtools}

\usepackage[active,displaymath,tightpage]{preview}
\setlength\PreviewBorder{1em}

\begin{document}
\[
y_v=\begin{cases*}
1,   &  if $v$ was received and decodable, \\
0,   &  otherwise
\end{cases*}
\quad   \forall v \in V 
\]
\end{document}