Finite State Automaton Language
Finite state automatons recognize regular languages. The advantage of regular languages is that it is usually trivial to express them formally.

FSA #1

$$L(M_1) = \left\{ a^kb^lc^m | k &gt; 0, l \geq 0, m \in \{ 0, 1 \} \right\}$$

FSA #2

$$L(M_2) = \left\{ a^kb^lc^m | k &gt; 0, l &gt; 0, m \in \{ 0, 1 \} \right\}$$