\begin{diagram}{Simple types}{simpletypes}
\begin{mysyntdiag}
\synt{simple\ type}
\begin{stack}
\synt{ordinal\ type} \\
\synt{real\ type}
\end{stack}
\end{mysyntdiag}
\begin{mysyntdiag}
\synt{real\ type} \synt{real\ type\ identifier}
\end{mysyntdiag}
\end{diagram}