4 a Form the truth tables for NAND the logical negation of t
     4. a) Form the truth tables for NAND (the logical negation of the AND operator) and NOR (the negation of the OR operator). b) By using a truth table, prove that (  P)  (  Q) =   (P VQ).     
 
  
  Solution
As the columns for (~P^~Q) and ~(PvQ) are both same together or false together
it implies that
(~P)^(~Q)=~(PvQ)
| P | Q | ~P | ~Q | (~P^~Q) | PvQ | ~(PvQ) | |
| T | T | F | F | F | T | F | |
| T | F | F | T | F | T | F | |
| F | T | T | F | F | T | F | |
| F | F | T | T | T | F | T | 

