\begin{diagram}{Libraries}{libraries}
\begin{mysyntdiag}
\synt{library}
\synt{library\ header} 
\lit* ; 
\[ \synt{uses\ clause} \]
\synt{block}
\lit* .
\end{mysyntdiag}
\begin{mysyntdiag}
\synt{library\ header}
\lit*{library} \synt{identifier}
\end{mysyntdiag}
\end{diagram}