This implementation uses 6 AND relay gates and 2 XOR relay gates to achieve the Boolean combinational logic for 2x2 binary multiplication.
The multiplicand and multiplier are represented by the logic sources at the bottom right. Note that binary convention is being observed so that the LSB (least significant bit) is the rightmost bit and the MSB (most significant bit) is the leftmost bit for each pair of logic sources.
The product is represented by the four LEDs (again following binary convention).
