# Aligned equations inside of TikZ node.

How can I create a tree node with an aligned math equations inside?

\begin{align}
\end{align}


doesn't work

\begin{minipage}{100}
\begin{align}
...
\end{align}
\end{minipage}


Gives a lot of margin and I don't want to manually tune 100.

\nodepart from shapes tikz library seems to be overkill and doesnt do the alignment.

Any ideas?

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You could use an aligned environment with inline math inside nodes, their size is automatically calculated. Here's a small example with such a node in a tree:

\documentclass{article}
\usepackage{tikz}
\usepackage{amsmath}
\begin{document}
\begin{tikzpicture}[every node/.style={rectangle,draw}]
\node {Example:}
child {node {%
\begin{aligned} a &= bx + c\\ a+b &= d +1 \end{aligned}}};
\end{tikzpicture}
\end{document}


Output:

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Great! it works. But why align doesn't? – Łukasz Lew Aug 8 '10 at 14:26
align is displayed, set off normal text and centered. Here it requires a minipage environment or \parbox, so it needs specifying a width. At least for the centering. – Stefan Kottwitz Aug 8 '10 at 14:40