When then opening and closing of a bracket are not on the same line, LaTeX demands 'invisible' brackets or it will get confused and not compile. Example:
\begin{equation}
\begin{aligned}
A = 5 & \left( a + b + c + ... \right. \\ % The '\right.' is invisible but needed to close the 'left)
& \left. d + e + f \right)
\end{aligned}
\end{equation}
I noticed that this behaviour doesn't work when instead of using \left(
you use \Big
(or any similar bracket size expression). The following doesn't compile:
\begin{equation}
\begin{aligned}
A = 5 & \Big( a + b + c + ... \right.
& \left. d + e + f \Big)
\end{aligned}
\end{equation}
It gives the following error:
? Missing } inserted.
<inserted text>
}
l.20 A = 5 & \Big( a + b + c + ... \right
. \\
?
What does this mean and how can I solve it?
Best Answer
With
\Big(
(or better\Bigl(
you do not need to close it: it is a self standing bracket.\left
\right
are different in that they need to see the intervening expression as a single math list in order to determine the size to stretch, which is why they can not span different cells in analign
.