Let A - aza2a1ag and B b3b2b1bbe 4-bit 2's complement numbers. Shown below is the structure of an arithmetic unit (AU), consisting of four 1-bit Full Adders (FAs), four copies of a circuit N, and interconnections as shown a3 b3 a2 b al b1 a0 bo k1 ko k1 ko k1 ko k1 ko a3* b3* b2* al b1* ao* c2 C1 CO FA FA FA FA S3 S0 As specified in the table below, the AU will compute an arithmetic function, depending on the values of control signals k1 and k0 k1 ko Function 0 0 2A+1 0 1 A-B 1 0 A-1 1 28-2 1. Express a and b" in minimal SOP form. Use K-maps to show your work. 2. Write a Boolean expression for co as a function of k1 and ko Let A - aza2a1ag and B b3b2b1bbe 4-bit 2's complement numbers. Shown below is the structure of an arithmetic unit (AU), consisting of four 1-bit Full Adders (FAs), four copies of a circuit N, and interconnections as shown a3 b3 a2 b al b1 a0 bo k1 ko k1 ko k1 ko k1 ko a3* b3* b2* al b1* ao* c2 C1 CO FA FA FA FA S3 S0 As specified in the table below, the AU will compute an arithmetic function, depending on the values of control signals k1 and k0 k1 ko Function 0 0 2A+1 0 1 A-B 1 0 A-1 1 28-2 1. Express a and b" in minimal SOP form. Use K-maps to show your work. 2. Write a Boolean expression for co as a function of k1 and ko