3. Let L1, L2, L3 and L4 be regular languages over accepted by DFAs M1 (Q1,2, 51,1A) , 4, s4,A4) respectively. My (Q2, , 2, si Ag), M,-(Qs, , 3: s3- An), and M4-(Q4, (a) Describe a DFA M a(Q, , , s, A) in terms of MI, M2, M3 and M4 that accepts L-(Li-L2) (L4 U Ls). Formally specify the components Q, , s, and A for M in terms of the components of Mi,M2, M3,M (b) Prove by induction that your construction is correct