# Long equation does not page break

I have a series of equations steps, about 20 lines or so. I would like to have it automatically decide page break when necessary, but it resists and always tries to stay in a whole page, rendering the previous page a lot of while space.

I tried \allowdisplaybreaks and \displaybreak, but doesn't seem to work.

{\allowdisplaybreaks$$\allowdisplaybreaks[4] \begin{split}\allowdisplaybreaks \alpha\beta\gamma&=abc\\ =def\\ =ghi\\ \end{split}$$}

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You need to use align and not split. – Werner Jan 29 '12 at 21:22
It seems to work with align. Thanks! – cpp initiator Jan 29 '12 at 21:57

Certain equation environments wrap their contents in an unbreakable box, with the consequence that neither \displaybreak nor \allowdisplaybreaks will have any effect on them. These include split, aligned, gathered, and alignedat.
It is not a bug in LaTeX. It is the behaviour described by the package manual. – Ian Thompson Dec 16 '12 at 16:30
You could justifiably argue that it is a limitation of the amsmath package, but it is neither a bug nor part of LaTeX itself. – Ian Thompson Dec 30 '12 at 18:04