4.
a) Considering A0, A1, B0, B1 as single bit data, configure a circuit
to implement F3 = (A1+B1) + (A0+B0) using appropriate adders
and justify your design.
b) Considering W, X, Y, Z as single bit data, design a digital circuit to
implement F4 = \overline{W}\overline{X}\overline{Y}\overline{Z} + 1 using appropriate gates and adder
units and justify your design.