(3) Explain in one line, how the equality in example 2.2.3 was obtained from properties of Boolean algebra. Example 2.2.3: Show that x' + x + x'y' + xyz evaluates to 1. Solution: Let e = x' + x + x'y' + xyz. According to precedence rules the last four operations performed are the + operations evaluated from left to right. As a result we have, e = x + x' + x'y' + xyz = (x + x') + x'y' + xyz = 1 + el, el = (x'y' + xyz) = 1 (by property 2a and 3a)