Complete list of answers to the questions asked about the NFA to FA example.

  1. Our goal is to create an FA M such that L(M) = L(N).

  2. Our upper bound on the number of states in M is 23 = 8. In general, if the NFA N had q states, the upper bound would be 2q.

  3. The strings that cause the FA M to end up in state {I,III} are

    (L(I) intersection L(III)) - (L(I) intersection L(II) intersection L(III)).

    How would you generalize this notion to an arbitrary FA M that simulates an arbitrary NFA N?

  4. {I,III}

    The NFA N can be in the state I because it is the initial state of N.

    It can also be in state III because of the epsilon transition from state I to state III.

  5. Because of the previous answer, the initial state of the FA M should be {I,III}.

  6. The accepting states of FA M should be {III},{I,III},{II,III}, and {I,II,III}.

    In general, the accepting states of M should be any subset of the state set of N that includes an accepting state.

    In this case, any subset of {I,II,III} that includes state III.

  7. The NFA N can transition to states I and II on character a from state I. Furthermore, because of the epsilon transition between states I and III, it can get to state III as well.

    Meanwhile, the NFA N can transition to state III on character a from state III.

    The answer is the union of these two sets which is {I,II,III}.

  8. The NFA N can transition to states II and III on character a from state II.

    Meanwhile, the NFA N can transition to state III on character a from state III.

    The answer is the union of these two sets which is {II,III}.

  9. state q delta(q,a) delta(q,b)
    {} {} {}
    I I,II,III II,III
    II II,III I,III
    III III II
    I,II I,II,III I,III
    I,III I,II,III I,II,III
    II,III II,III I,II,III
    I,II,III I,II,III I,II,III

    I left out the braces except for the empty set because I found them to be visually confusing.