Lesson 1010: Testing Equality with Truth Tables

There are two ways to test equality with truth tables. It is up to you to decide which you like better based upon which you feel is organized better, and which is easier for you.

The first, and probably most organized, requires that you evaluate each boolean expression that you are testing for equality on a separate truth table.

We can clearly see from the resluts of the truth tables that the two expressions are not equivalent. Using truth tables often is quicker than trying to simplify larger boolean expressions using boolean algebra.

The second method for using truth tables to test equality of boolean expressions is by using a single truth table to evaluate both or all expressions.

This method is easier than the first, but is more disorganized and less obvious to another reader that you have proved something.

Test the following two expressions for equality using the two truth table skeletons below.

(A+B)AB and (A+B)(AB)

 | | | | (A+B)AB 
---+---+-----+----+---------
 | |   |  |   
 | |   |  |   
 | |   |  |   
 | |   |  |   


 | | | A@B | (A+B)(A@B)
---+---+-----+-----+------------
 | |   |   |    
 | |   |   |    
 | |   |   |    
 | |   |   |