\begin{frame}{Example}
\begin{exampleblock}{}
Consider the TM with $\Sigma=\{a,b,c\}$, $\Gamma=\Sigma\cup\{\Box\}$, $F=\{q_2\}$ and
\begin{talign}
\delta(q_0,a) &= (q_0,c,R) & \delta(q_0,c) &= (q_1,b,L) \\
\delta(q_0,b) &= (q_0,b,R) & \delta(q_1,b) &= (q_2,a,R)
\end{talign}
This TM accepts the language \alert{$L((a+b)^*bc(a+b+c)^*)$}.
\end{exampleblock}
\pause
\begin{exampleblock}{}
The resulting grammar is:
\pause
\begin{talign}
S &\to V_\Box^\Box S \mid S V_\Box^\Box \mid T \\[-.25ex]
T &\to T V_a^a \mid T V_b^b \mid T V_c^c \mid V_{q_0a}^a\mid V_{q_0b}^b\mid V_{q_0c}^c
\end{talign}\vspace{-3ex}
\begin{talign}
V_{q_0a}^{\alert{\alpha}}V_{\alert{\gamma}}^{\alert{\beta}}
&\to V_c^{\alert{\alpha}}V_{q_0\alert{\gamma}}^{\alert{\beta}} &
V_{q_2\alert{\gamma}}^{\alert{\alpha}}
&\to \alert{\alpha} \\[-.25ex]
V_{q_0b}^{\alert{\alpha}}V_{\alert{\gamma}}^{\alert{\beta}}
&\to V_b^{\alert{\alpha}}V_{q_0\alert{\gamma}}^{\alert{\beta}} &
\alert{\beta} V_{\alert{\gamma}}^{\alert{\alpha}}
&\to \alert{\beta \alpha} \\[-.25ex]
V_{\alert{\gamma}}^{\alert{\beta}}V_{q_0c}^{\alert{\alpha}}
&\to V_{q_1\alert{\gamma}}^{\alert{\beta}}V_b^{\alert{\alpha}} &
V_{\alert{\gamma}}^{\alert{\alpha}} \alert{\beta}
&\to \alert{\alpha \beta} \\[-.25ex]
V_{q_1b}^{\alert{\alpha}}V_{\alert{\gamma}}^{\alert{\beta}}
&\to V_a^{\alert{\alpha}}V_{q_2\alert{\gamma}}^{\alert{\beta}} &
\Box &\to \lambda
\end{talign}
with $\alert{\alpha}, \alert{\beta} \in \Sigma\cup\{\Box\}$ and $\alert{\gamma}\in\Gamma$.
\pause
\structure{Exercise}: derive $abc$.
\end{exampleblock}
\end{frame}