\begin{tikzpicture}[program,initial above,font=\scriptsize,
every state/.append style={rectangle,rounded corners=10},
]
\node[state,initial] (l0t) {$\langle \ell_0, \texttt{true} \rangle$};
\node[state] (l1t) [below=2cm of l0t] {$\langle \ell_1, \texttt{true} \rangle$};
\node[state] (l2t) [below=2cm of l1t] {$\langle \ell_2, \texttt{true} \rangle$};
\node[state,grun] (l1p134) [right=4cm of l1t] {$\langle \ell_1, \lbrace \psi_1, \psi_3, \psi_4 \rbrace \rangle$};
\node[state,grun] (l1p124) [right=4cm of l2t] {$\langle \ell_1, \lbrace \psi_1, \psi_2, \psi_4 \rbrace \rangle$};
\path[->]
(l0t) edge[] node (t0) { $t_{0}$ } (l1t)
(l1t) edge[bend left=20] node (t1) { $t_{2}$ } (l2t)
(l2t) edge[bend left=20] node (t2) { $t_{3}$ } (l1t)
(l1t) edge[grun, bend left=10] node (t1a1) { $t_{1a,1}$ } (l1p134)
(l1t) edge[grun, bend left=10] node[pos=0.35] (t1b1) { $t_{1b,1}$ } (l1p124)
(l1p134) edge[rot, bend left=10] node[pos=0.65] (t21) { $t_{2,1}$ } (l2t)
(l1p124) edge[rot, bend left=10] node (t22) { $t_{2,2}$ } (l2t)
(l1p134) edge[rot,loop above] node (t1a2) { $t_{1a,2}$ } ()
(l1p124) edge[rot,loop below] node (t1b3) { $t_{1b,3}$ } ()
(l1p134) edge[rot, bend right=20,transform canvas={xshift=5mm}] node[swap] (t1b2) { $t_{1b,2}$ } (l1p124)
(l1p124) edge[rot, bend right=20,transform canvas={xshift=5mm}] node[swap] (t1a3) { $t_{1a,3}$ } (l1p134)
;
\node[] [below right=1cm of l0t] {$G_0$};
\node[grun] [above left=1cm of l1p134] {$G_1$};
\node[rot] [below right=2cm of l1p134] {$G_2$};
\end{tikzpicture}