Is there an alternative of \arraycolsep for cases environment?

Question

I have this problem:

I can control the space in array environment with \arraycolsep, but it doesn't work in cases environment. Is there an alternative of \arraycolsep for cases environment?

\documentclass{article}
\usepackage{amsmath}
\begin{document}
\setlength{\arraycolsep}{2.2pt}
$\begin{array}{cl}
    4x-5y =23&  \scriptstyle |\cdot 3\\
    6x+7y=-9&  \scriptstyle |\cdot (-2)
\end{array}$
$\begin{cases}
    4x-5y =23&  \scriptstyle |\cdot 3\
    6x+7y=-9&  \scriptstyle |\cdot (-2)
\end{cases}$
\end{document}

Answer 1

You can use systeme.

\documentclass{article}
\usepackage{systeme}
\begin{document}
[
\systeme{
  4x - 5y = 23 @ \scriptstyle|\cdot3,
  6x + 7y = -9 @ \scriptstyle|\cdot(-2)
}
]
[
\syscodeextracol{\hspace{0.5em}$}{$}
\systeme{
  4x - 5y = 23 @ \scriptstyle|\cdot3,
  6x + 7y = -9 @ \scriptstyle|\cdot(-2)
}
]
[
\syscodeextracol{\hspace{0.5em}$\scriptstyle|\cdot}{$}
\systeme{
  4x - 5y = 23 @ 3,
  6x + 7y = -9 @ (-2)
}
]
\end{document}

The \syscodeextracol command can go in the preamble and affect every \systeme in the document. In the last example I show how you can refine the customization.

The default separation is \hspace{1.5em}.