On 5/24/05, Áú ·É <longf77@hotmail.com> wrote:
> I try to use:
> \startformula
> \left\{ \begin{array}{r@=l}
> xx & yy \\
> zz & aa
> \end{array} \right.
> \stopformula
> But Context log says
> "Undefined control sequence \begin{array}."

\begin{array} comes from LaTeX.

> How can I input multi-line equation in ConTeXt? Thanks

You can use \matrix from plain TeX:

\startformula
\left\{\matrix{
	xx & yy \cr
	zz & aa}
\right.
\stopformula

I'm not sure if there's any mechanism for automatic (right/left)
alignment. I use \hfill if necessary. (xx\hfill yy\hfill \cr ...)

Mojca