In the Sets category, given sets A and B with A = \{a, b, c, ..., z\} then if B_a = \{a\} \times B , B_b = \{b\} \times B , ..., B_z = \{z\} \times B , then the product of A and B is A \times B = B_a \cup B_b \cup ... \cup B_z and the exponential is B^A = B_a \times B_b \times ... \times B_z .