17.6 DE MORGAN'S LAWS
De Morgan, a mathematician, stated two important rules for group complementation in Boolean algebra. These are known as De Morgan’s laws.
Law 1: This law states that the complement of a sum of variables is equal to the product of their individual complements, shown in Fig. 17.14(a).
De Morgan’s first law allows the breaking of one bar at a time, generally, starting with the longest bar. Consider When the bar is broken, the resultant expression is . This means that a NOR is converted as a negative AND, as shown in Fig. 17.14(b) ...