# How to provide more horizontal space between cases in a system?

I have the following ugly system:

This is my LaTeX code:

\newcommand{\Aaa}{\begin{bmatrix} 1 & 0 \\ 0 & -1\end{bmatrix}}
\newcommand{\Ba}{\begin{bmatrix} 0 & 1 \\ -1 & 0\end{bmatrix}}
\newcommand{\R}{\mathbb R}

\begin{displaymath}
f: G\longrightarrow GL_2(\R):
\begin{cases}
a\longmapsto \Aaa\\
b\longmapsto \Ba
\end{cases}
\end{displaymath}


As you can see, the matrices 'collide'. Is it possible to add some more blanc space between them?

• Love the speech bubble! :D – Alenanno Nov 1 '13 at 0:11
• Haha, adding some more fun to mathematics. :D – Jeroen Nov 1 '13 at 0:13

\end{document}


Using the tabstackengine package introduced at Writing a table with equally spaced columns, based on the widest column, you can control the vertical gap between the matrix rows as well as between the "cases", and the horizontal gap between matrix elements.

\documentclass{article}
\usepackage{tabstackengine}
\usepackage{amssymb}
\begin{document}
\setstackgap{L}{1.3\baselineskip}%BASELINE SHIFT BETWEEN MATRIX ELEMENTS
\setstacktabbedgap{2ex}% HORIZONTAL GAP BETWEEN MATRIX ELEMENTS
\savestack\Mone{$\bracketMatrixstack[c]{1&0\\0&-\!1}$}
\savestack\Mtwo{$\bracketMatrixstack[c]{0&1\\-\!1&0}$}
\setstackgap{L}{2.8\baselineskip}% BASELINE SHIFT BETWEEN CASE ROWS
f: G\longrightarrow GL_2(\mathbb{R}): \left\{\raisebox{.3\baselineskip}{% .3 IS AN AD HOC CORRECTION \alignVectorstack{a&\longmapsto \Mone\\b&\longmapsto \Mtwo}} \right.
\end{document}