> 4. (10 points) For the function f(w1,w2,w3)=w1 w3 +w1w2 +w2w3, use Shannon expansion to derive an implementation using 4-to-1 multiplexer and variables wlw2 as control values. Make sure to show the appropriate co-factors and to draw the logic circuit that represents the implementation of this function (you do not need to show the logic implementation of the multiplexer, only the logic connected to its input)