At 04:42 PM 9/12/2005, you wrote:
I have tried with:
\startcases .. \stopcases
and many others variations but I have got only errors. Any hint?
Much like the bmatrix environment, the cases environment is an AMSmath package feature, and ConTeXt at present has very few of the direct equivalents to those implemented. You'll need to make this one up with a Plain TeX \matrix, as well. (The TeXbook is a pretty good reference for this.) Something like this should work, to recreate the example from page 8 of the AMSmath manual: P_{r-j} = \left\lbrace \matrix{ 0 \hfill& \text{if $r-j$ is odd} \hfill\cr r!(-1)^{(r-j)/2} \hfill& \text{if $r-j$ is even} \hfill\cr } \right. The \left\lbrace and \right. create the properly expanded brace at the left, the \matrix handles putting things in the right places, the \hfills make each of the columns left-aligned, and the \text{} commands (which _do_ exist in ConTeXt, unlike in Plain TeX) typeset their arguments as text rather than math. - Brooks