How to Use:
- If the question asks you to show A ==> B (A implies B, where A and B are statements), then it is equivalent to show ~B ==> ~A (not B implies not A)
Reasons to Use:
- The amount of cases needed to validate ~B ==> ~A is finite, or significantly smaller, in comparison to the amount of cases needed to validate A ==> B
Click here to view just the question for the example proof by contrapositive. If you would like to see the worked out solution to the proof by contrapositive problem, click here.