\item \lect Draw the graph for a \emph{transition system} $\mathcal{T}$ with: 
$S = \{s_1, s_2, s_3, s_4\}, $\\
$S_0 = \{s_2\}, $\\
$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\}\}, $