Math & Science ⇒ Breaking lines in the align environment.

[GleasSpty]

Normally, when I try to break lines in the align environment, everything works perfectly line. However, if I try to make a line break inside brackets, for example, created with the \left[ / \right] commands, Latex throws tons of errors and won't typeset anything at all after the line break.

Is there any way around this? How can I perform a line break inside brackets (or parentheses, or curly braces, etc.)?

[localghost]

In a line there has always to be a complete pair of \left and \right delimiters. In case such a pair spreads over two or more lines, you have to balance that with according invisible delimiters \left. and \right. in order to avoid errors.


Best regards and welcome to the board
Thorsten¹

[GleasSpty]

When I did this, everything typset correctly (as far as I can tell); however, Texniccenter is still throwing errors at me: 4 to be prcise. They all say "Missing delimeter".

It's not that big of a deal because the output is what it should be, but is there any way to eliminate these errors as well?

Thanks much!

[localghost]

Show the relevent code embedded in a minimal working example (MWE).

[GleasSpty]

Here is the relevant line:

Code: Select all

\documentclass{article}
\usepackage{amsmath,amssymb}
\begin{document}

\begin{align*}
\nabla ^2v & =2\left[ \left( \left( \frac{\partial ^2u}{\partial x^2}\right) ^2+\frac{\partial u}{\partial x}\frac{\partial ^3u}{\partial x^3}+\left( \frac{\partial ^2u}{\partial x\partial y}\right) ^2+\frac{\partial u}{\partial y}\frac{\partial ^3u}{\partial x^2y}\right) \right \\
& +\left \left( \left( \frac{\partial ^2u}{\partial y^2}\right) ^2+\frac{\partial u}{\partial y}\frac{\partial ^3u}{\partial y^3}+\left( \frac{\partial ^2u}{\partial x\partial y}\right) ^2+\frac{\partial u}{\partial x}\frac{\partial ^3u}{\partial xy^2}\right) \right]
\end{align*}

\end{document}

The error reads:
Missing delimiter (. inserted ).

[localghost]

As mentioned earlier, you have to balance a single delimiter with an invisible one to make the pair complete (see »Math Miscellany«).

Code: Select all

\left. \ldots \right)

[GleasSpty]

Oops. Sorry about that. I didn't see the period there before. Anyways, I have resolved the problem now.

Thanks a lot!

[olofos]

In general I think it's better to manually adjust the size of the delimiters using \big or it's cousins, when the start and end brackets are on different lines. This makes sure that both brackets are of the same size. Another option is to use the breqn package, which seems very powerful, though I never actually used it myself.