# Aligning long broken equation (with brackets also split over multiple lines)

I have long equation $F=\left\{ abcdef \right\}$ which needed to break line at halfway. To do it I use \begin{multline}.

\begin{multline}
F =  \left\{   abc \right.\nonumber\\
\left. {}  +  def \right\},
\end{multline}


I also need to break curly bracket over the multiple lines, which I do with \right.\nonumber\\.

q1) How to align the equals sign of top line with + sign of bottom line in this case?

q2) How to display equation number?

## 1 Answer

First option does what you want, although I prefer second solution with + not aligned with =.

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{mathtools}
\begin{document}

$$\begin{split} F = & \left\{ abc \right.\\ + & \left. def \right\} \end{split}$$

$$\begin{split} F = & \left\{ abc \right.\\ & + \left. def \right\} \end{split}$$
\end{document}


• You assume that height of the first line is the same as of second one. If this is not true, than curly brace will not have the same heights. Maybe will better to use for example \big\{ or \bigl\{ etc – Zarko May 19 '16 at 14:13
• @Zarko I don't assume it, I've only used what Nigel1 posted. In any case the question doesn't mention this aspect. – Ignasi May 19 '16 at 14:17