Q$5$

Let ${\displaystyle \underset{?}{\overset{?}{}}}=\{L,O\},L$ is any letter, O is any other symbol

Find a finite automaton without $-$transitions and with a single final state which accepts any

password P with the following rules:

$|P|4$

P begins with a letter $($L$)$ and ends with a letter $($L$)$

P contains at least one other symbol $($O$)$

Every two consecutive other symbols$($OO$)$ must be followed immediately by a letter $($L$)$

Given the following :

$L_1$ is denoted by $b(c+ac)a^{*}{b}^{*}{c}^{*},L_2$ is denoted by $\{d,e,f{\}}^{*}$ except $\{$:$\{f^n$:$n0\}U\{e,ed\}\}$

Is it possible to find an FA without $$ transitions and with no more than two final states

for $L_{1}U{L}_2?.$

If no explain why. If yes explain how

Is it possible to find a regular expression for the language generated by the grammar $?$

$S$ABC$|deD|cS$

$ABB|a$

$BAB|b$

$CccCc|c|cc$

$D|dEe$

$E$ Eee $|d$

If no explain why. If yes explain how