Let us consider an automaton that recognizes words that contain at least two copies of the symbol "-". Let us only consider the alphabet consisting of three symbols: "-", "a", and "b". This automaton has 3 states:
- The start state "s" corresponding to no minuses;
- The intermediate state "i" corresponding to words with exactly one minus; and
- The final state "f" corresponding to words with two or more minuses.
Transitions are as follows:
- From the state "s", minus leads to "i", and other symbols lead back to "s".
- From the state "i", minus leads to "f", and other symbols lead back to "i".
- From the final state "f", every symbol leads back to "f".
This automaton accepts the word "a--".