# How to use \displaybreak?

I have a very long equation

\begin{equation*}
\begin{aligned}
multiple line equation...
\end{aligned}



But just using the above code causes the whole equation to start from a new page leaving behind a third of previous page empty. Where should i put the \displaybreak command to ensure that the page breaks occurs conveniently in between the equation. I tried using it in the following manner but it doesn't help.

\begingroup
\allowdisplaybreak
\begin{equation*}
\begin{aligned}
multiple line equation...
\end{aligned}

\endgroup

• The point is that, aligned environment wraps its contents inside an unbreakable box. So, these commands (both \displaybreak and \allowdisplaybreaks) do not have any effect. You may want to look at texdoc.net/pkg/amsldoc, towards the end of page 6. – kan May 4 '13 at 10:27
• You have to use align* for \displaybreak to work. – egreg May 4 '13 at 10:33
• @egreg i tried using \begin{align*} instead of \begin{aligned}. But i still get the following error ! Undefined control sequence. \allowdisplaybreak and ! Package amsmath Error: Erroneous nesting of equation structures;(amsmath) trying to recover with 'aligned' – Pratap Dheeraj May 4 '13 at 12:56
• It's \allowdisplaybreaks. – egreg May 4 '13 at 13:00

The point is that, aligned environment wraps its contents inside an unbreakable box. So, these commands (that is, both \displaybreak and \allowdisplaybreaks) do not have any effect.

This is true of split, gathered and alignedat environments too.

So, to get the line break to work, you might consider using align*, as suggested by egreg.

You might want to refer to amsldoc, towards the end of page 6 for these comments. I'd also like to draw your attention to the section 3 of this document for discussions regarding display math.

By the way, please note that, you have s missing in \allowdisplaybreaks.