# NFA to DFA Conversion Help

Consider the language of all words over {a, b} that either begins and ends with aa or bb (but both are the same within each word). That is, {ccycc | c ∈ {a, b}, y ∈ Σ ∗}

I have drawn the resulting NFA for the language described above, what would the corresponding DFA look like? What would the steps look like to get from an NFA to a DFA?

• That doesn’t quite work: you end up accepting $aaaabb$, which is not in the language. Feb 12 '21 at 17:50
• Almost, but you need the $b$ transition from $q_8$ to go to $q_4$, and the $a$ transition from $q_7$ to go to $q_3$. As it stands, it accepts $aabaaba$, which it should not do. Feb 12 '21 at 18:28