[math]\displaystyle{
\newenvironment{rcases}
{\left.\begin{align*}}
{\end{align*}\right\rbrace}
\newenvironment{lcases}
{\left\lbrace\begin{align*}}
{\end{align*}\right.}
}[/math]
This template allows LaTeX representations of cases by defining operators in advance to avoid the need to manually enter brackets.