\item \lect Draw the graph for the \emph{transition system} $\mathcal{T}$ with:
\begin{itemize}[itemsep=-0.9em, leftmargin=0.8em]
\item $S = \{s_1, s_2, s_3, s_4\}, $\\
\item $S_0 = \{s_2\}, $\\
\item $R = \{\{s_1, s_2\}, \{s_1, s_1\}, \{s_2, s_4\}, \{s_2, s_3\}, \{s_3, s_1\}, \{s_4, s_2\}, \{s_4, s_3\}\}, $
\end{itemize}