6. Design an AND-OR circuit that outputs 1 if its 4-bit input contains an even number of ls and 0 otherwise. Consider 0 an even number. 7. Express the function F (A,B,C,D) = A'B'(C+D) + C'(A+B'C') in: a) Canonical SOP form b) Canonical POS form c) Minterm List form d) Maxterm List form