Introduction to Logic
by
Stefan Waner and Steven R. Costenoble

Answers to Exercises
for
Section 5: Rules of Inference

4. Tautological Implications and Tautological Equivalences 5. Rules of Inference 6. Arguments and Proofs Main Logic Page Main Logic Page "Real World" Page
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1. ~q

3. ~(qr)

5. ~(~pq)

7. p~q

9. (pr)r

11. 4. (pr)r; 5. ~(pr)

13. pq

15. 3. (~r)(~q); 4. ~(rq); 5. ~p

17. 4. pq; 5. r

19. De Morgan

21. 1,2 Modus Tollens

23. 1, Switcheroo

25. 1, Switcheroo; 2, De Morgan

27. 2, Addition; 1,3 Modus Ponens; 4, Simplification

29. 1,2 Transitive Law; 4, Contrapositive; 3,5 Modus Ponens

31. 1, Simplification; 1, Simplification; 3, Addition, 4, Switcheroo; 2,5 Modus Ponens

33. Double Negative; Double Negative (S); 2, Switcheroo; 3, Addition; 4, Associative Law; 5, Commutative Law; 6, Switcheroo; 7, Switcheroo

4. Tautological Implications and Tautological Equivalences 5. Rules of Inference 6. Arguments and Proofs Main Logic Page "Real World" Page
Return to Exercises

We would welcome comments and suggestions for improving this resource. Mail us at:
Stefan Waner (matszw@hofstra.edu) Steven R. Costenoble (matsrc@hofstra.edu)
Last Updated: July, 1996
Copyright © 1996 StefanWaner and Steven R. Costenoble