A = {1, 2, 3}, B = {4, 5, 6}
∴ A × B = {(1, 4), (1, 5), (1, 6), (2,4), (2, 5), (2, 6), (3, 4), (3, 5), (3, 6)}
R1 = {(1, 4), (1, 5), (1, 6)}
Since R ⊆ A × B,
R1 is a relation from A to B.
Domain (R1) = Set of first components of R = {1}
Range (R1) = Set of second components of R = {4, 5, 6}