EXAMPLE 2.3.10 Solution

Let p be the statement "I get elected."

Let q be the statement "I reduce taxes."

Let r be the statement "The economy will prosper."

 

The argument has this symbolic form:

 

If you make a truth table having a column for each premise and a column for the conclusion, you will see that the argument is VALID.

 

Here's the truth table:



Notice that in this truth table there is NO ROW in which both premises are true while the conclusion is false. The absence of such a "bad row" indicates that the argument is VALID.