Problem 1:Using four half addersa) Design a full subtractor circuit incrementor. (A circuit that addsone to a four-bit binary number).b) Design a four bit combinational decrementor. (A circuit thatsubtracts one from a four-bit binary number).Problems 2:Construct a 16 X 1 multiplexer with two 8 X 1 and one 2 X 1multiplexers. Use block diagrams.Problem 3:Implement the following Boolean function with a 4 X 1 multiplexerand external gates.

Full Subtractor Circuit and Its Construction