2 Define a Scheme procedure (bit Adder x a b) to simulate the logic design given in the diagram in Figure 2. The procedure must follow the design in Figure and call the gate procedures that you d c), where s is the binary sum of a, b, and x, while c is the carry-out. You will implement the procedure in three steps using three procedures, as listed below. in Question 1 and must return a pair with two elements (s