1. Give a regular description for the set of words over {a,b} such there is exactly one occurrence of aaa and of bbb.

2. Give a regular description for the set of words over {a,b} such that there is an a at positions six from the end, and there is at least one occurrence of bbb.

3. Give a regular description for the set of words w over {0,1} such that the natural value obtained by interpreting w as a binary number, that is , is multiple of 12 (in particular, the empty word represents 0, which is multiple of 12).

4. Regular description for the language recognized by the NFA with set of states {0,1,2,3,4,5} initial state 0, accepting state 4, and transitions

5. Regular description for the language recognized by the NFA with set of states \{0,1,2,3,4,5\}{0,1,2,3,4,5}, initial states {2,5} accepting state 4, and transitions

value2(w