\(V=\{v,w\}, A=\varnothing\)
The second condition of the set comprehension is vacuously satisfied because \(A = \varnothing\)
So all we have left is all pairs of tuples where the first element comes from \(D(v)\) and the second element comes from the set \(D(w)\).
This is the Cartesian product \(D(v) \times D(w)\)