- \begin{tikzpicture}[node distance=7em]
- \node (1) {$No Value$};
- \node (2) [right of=1] {$Unstable$};
- \node (3) [right of=2] {$Stable$};
+ \begin{tikzpicture}[node distance=7em,nodes={draw,minimum width=5em}]
+ \node (1) {no value};
+ \node (2) [right of=1] {unstable};
+ \node (3) [right of=2] {stable};