# Is there a ConTeXt version of the LaTeX lefteqn?

What I want is to be able to set up equations like this:

a very long first expression
= the second line
= and a third line
= and maybe even a fourth


In LaTeX, this would be done with the array environment and lefteqn. A look through the excellent documents on math in ConTeXt doesn't seem to answer my question. So - how do I do this in ConTeXt?

Thanks very much!

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Please consider marking some answers to your questions as as ‘Accepted’ by clicking on the tickmark below their vote count. This shows which answer helped you most, and it assigns reputation points to the author of the answer (and to you!). –  Caramdir Mar 4 '11 at 20:50

I usually use:

\startformula \startalign
\NC \hskip 2em \NC hskip -2em
A very long first expression \NR
\NC \EQ the second line \NR
\NC \EQ the third line \NR
\stopalign \stopformula


Of course, you can wrap \NC \hskip 2em \NC \hskip -2em in a macro, if you wish. FWIW, I use a similar approach in LaTeX.

\begin{align}
\hskip 2em & \hskip -2em
A very long first expression \\
&= the second line \\
&= the third line
\end{align}


The advantage is that I can then control if I want to split the equation across pages.

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@Alasdair: Since you seem happy with this answer, please consider marking it as ‘Accepted’ by clicking on the tickmark below the vote count. This shows that answer helped you, and it assigns reputation points to the author of the answer (and to you!). –  Joseph Wright Mar 18 '11 at 23:19