Hello, I need help writing proofs for a logic and moral reasoning philosophy class. The proofs are for: 1. Premises: q -> (q &~ q) Conclusion: ~q 2. Premises: k & l
HW 11
Write proofs for the following problems.
(2)
Premises:
x -> (y & z)
y -> (w & ~w)
~x -> w
Conclusion:
| |
| |
| |
-4. ~w | SA |
-5. ~~x | MT 3, 4 |
-6. x | DN 5 |
-7. y & z | MP 1, 6 |
-8. y | Simp 7 |
-9. w & ~w | MP 2, 8 |
10. ~~w | IP 4-9 |
11. w | DN 10 |
(4)
Premises:
(~a) -> ((b & c) V (b & d))
~(e V b)
Conclusion:
| |
| |
-3. ~a | SA |
-4. (b & c) V (b & d) | MP 1, 3 |
-5. ~e & ~b | DM 2 |
-6. ~b | Simp 5 |
--7. b & c | SA |
--8. b | Simp 7 |
--9. b & ~b | Conj 8, 6 |
-10. ~(b & c) | IP 7-9 |
--11. b & d | SA |
--12. b | Simp 11 |
--13. b & ~b | Conj 12, 6 |
-14. ~(b & d) | IP 11-13 |
-15. ~(b & c) & ~(b & d) | Conj 10, 14 |
-16. ~((b & c) V (b & d)) | DM 15 |
-17. ((b & c) V (b & d)) & ~((b & c) V (b & d)) | Conj 4, 16 |
18. ~~a | IP 3-17 |
19. a | DN 18 |
~(p & q) ~(p V q)
________ _______
~p V ~q ~p &~q
(6)
Premises:
(x V y) & (x V z)
z -> w
~(w & z)
Conclusion:
| |
| |
| |
-4. ~x | SA |
-5. x V z | Simp 1 |
-6. z | DS 5, 4 |
-7. w | MP 2, 6 |
-8. ~w V ~z | DM 3 |
-9. ~~w | DN 7 |
-10. ~z | DS 8, 9 |
-11. z & ~z | Conj 6, 10 |
12.~~x | IP 4-11 |
13. x | DN 12 |
(8)
Premises:
b V (~c)
(~c) -> (~a)
Conclusion:
(~a) V b
| |
| |
-3. a | SA |
-4. ~~a | DN 3 |
-5. ~~c | MT 2, 4 |
-6. b | DS 1, 5 |
7. a -> b | CP 3-6 |
8. ~a V b | MI 7 |
(10)
Premises:
p <-> q
Conclusion:
(~p) <-> (~q)
| |
| ME 1 |
| Simp 2 |
| Simp 2 |
-5. ~p | SA |
-6. ~q | MT 4, 5 |
7. ~p -> ~q | CP 5-6 |
-8. ~q | SA |
-9. ~p | MT 4, 5 |
10. ~q -> ~p | CP 8-9 |
-11. (~p -> ~q) & (~q -> ~p) | Conj 7, 9 |
12. ~p <-> ~q | ME 11 |
(12)
Premises:
p -> q
r V p
~(q & r)
Conclusion:
p <-> q
| |
| |
| |
-4. q | SA |
-5. ~q V~r | DM 3 |
-6. ~~q | DN 4 |
-7. ~r | DS 5, 6 |
-8. p | DS 2, 7 |
9. q -> p | CP 4-8 |
10. (p -> q) & (q -> p) | Conj 1, 9 |
11. p <-> q | ME 10 |