3. A half subtractor subtracts two bits, x and y producing their difference d. It also has an output b to specify if a 1 has been borrowed from the next higher position The truth table is given below. Following the steps from the notes, produce the "Half Subtractor" device. Then, use the device and connect binary switches and binary probes to test the truth table. Write the boolean function for d and b beside the circuit. Input Output x y bd 00.00 010111 10001 110DD Hand-In The underlying circuit of the "Half Subtractor" device. (Circuit with labeled ports--Part 1 in the notes) Boolean functions for borrow (b) and difference (d) The testing circuit of the "Half Subtractor"device (the box) with binary switches and binary probes connected to it 4. Using the property that: @y-xy - xy show that a half subtractor can be implemented using a "Half Adder" device and two inverter gates. Build and test this circuit with the truth table. Write the expressions of the difference and the borrow beside the circuit Hand-In The half subtractor circuit using the "Half Adder" device and two NOT's Boolean functions for Difference and Borrow (will be slightly different from 3, because of inverters--consider what is going into the box and what is coming out of the box)