2. (25 points) Use the method that we studied in the class to convert the following DFA to a regular expression. You must remove states in the order of 0, 1, 2, and 3. Please show the equivalent GNFA in the special form (5 points), the equivalent NFA after removing state 0 (5 points), the equivalent GNFA after removing state 1 (5 points), the equivalent GNFA after removing state 2 (5 points), and the equivalent GNFA after removing state 3 (5 points) a