Cross Product Method over DFAs
We will try to understand this property using one example.

So as you see in the above picture, we have taken two DFAs
- Even no of a's
- Even no of b's
- L1 = {ε, baa, aa, aba, aab, aaaa, ... }
- L2 = {ε bb, abb, bab, bba, ...}
After taking cross product we will find the below DFA, already we have seen this DFA in previous exampels
As, L = {ab, aab, abb, aaab, ...}
How we have designed:
{A, B} X {C, D} = {AC, AD, BC, BD}
We should know the transition of the above four states
You can also take some examples from the previous exercises for practice.