Math & Science ⇒ how to type this formula

[drowsy]

Here: http://img231.imageshack.us/img231/7407/exampleyp8.jpg

If there is just one function I use cases, but with two ? It would be nice to center "and" in the middle between the two lines too.

[mas]

This worked for me.

Code: Select all

\documentclass{article}
%
\usepackage{amsmath,amssymb}

\begin{document}

\[
  f = \begin{cases}
         f_1 \text{ on } X_1 \\
         f_2 \text{ on } X_2
      \end{cases}
      \text{ and }
  g = \begin{cases}
         g_1 \text{ on } Y_1 \\
         g_2 \text{ on } Y_2
      \end{cases}
\]      

\end{document}

Regards.

[drowsy]

Oops, thank you.

I just forgot that I did it like this long time ago and it worked