a) Consider the full adder function: i-1 i i i i sum(c , x , y ) = (c , s) Where xi i i-1 , y are the i bits of the binary numbers X and Y, c is the carry in and the outputs are: th ci i , the carry out and s is the sum output. Write the equations o i i f both c and s in conjunctive normal form (CNF), i.e. in standard product of sums (SPOS). b) As a result of a) above, design the corresponding circuit for the full adder, using only the NOR gates..