Line spacing in TikZ multiline nodes inside tables

Question

I'm trying to typeset some multiline TikZ nodes inside a tabular environment. Somehow, the space between lines gets considerably shortened.

Here's my code:

\documentclass{article}
\usepackage{tikz}
\begin{document}

\begin{tikzpicture}
    \node [align=center] {
    \underline{$(\alpha \land \beta)$}\\
    $\alpha$\\
    $\beta$
    };
\end{tikzpicture}

\begin{tabular}{c}
    \begin{tikzpicture}
        \node [align=center] {
    \underline{$(\alpha \land \beta)$}\\
        $\alpha$\\
        $\beta$
        };
 \end{tikzpicture}
\end{tabular}

\end{document}

Can someone explain what is happening and how can I prevent it?

Answer 1

You could save the tikzpicture in a box, outside of the tabular, and then use it once you're inside the tabular. What I mean is...

\documentclass{article}
\usepackage{tikz}
\begin{document}
\newsavebox\john
\sbox\john{
\begin{tikzpicture}
    \node [align=center] {
    \underline{$(\alpha \land \beta)$}\\
    $\alpha$\\
    $\beta$
    };
\end{tikzpicture}
}

\begin{tabular}{c}
\usebox\john
\end{tabular}
\end{document}

---

By the way, if you're drawing proof trees, you might find the bussproofs or mathpartir packages helpful.