1) Simplify the following circuits using bubble pushing. The simplified circuits should have only the specified gates under the circuits Y2 Y1 NOT, NAND, NOR) NOT, AND, OR) Y4 Y3 Dr NOT, NAND,XNOR) NOT, NAND, NOR, XNOR) 2) Write the Boolean functions of above circuits (Y1, Y2,Y3 and Y4) in Sum of products (SOP) form Product of sums (POS) form. a. b