Jesse Rappaport
Course slides for Professor Rappaport
PREMISES:
(s V t) -> (s -> ~t)
(s -> ~t) -> (t -> k)
s V t
CONCLUSION:
s V k
PROOF
1. (s V t) -> (s -> ~t) PREMISE
2. (s -> ~t) -> (t -> k) PREMISE
3. s V t PREMISE
4. (s V t) -> (t -> k) H.S. (1, 2)
5. t -> k M.P. (3, 4)
6. ~s -> t Impl. (3)
7. ~s -> k H.S. (5, 6)
8. ~~s V k Impl. (7)
9. s V k D.N. (8)
PREMISES:
h -> u
CONCLUSION:
h -> (u V t)
PROOF
1. h -> u PREMISE
2. h ASSUMPTION
3. u M.P. (1, 2)
4. u V t Addition (3)
5. h -> (u V t) Conditional Proof (2, 4)
PREMISES:
q -> (w & d)
CONCLUSION:
q -> w
PROOF
1. q -> (w & d) PREMISE
2. ~q V (w & d) Impl. (1)
3. (~q V w) & (~q V d) Dist. (2)
4. ~q V w Simp. (3)
5. ~~q -> w Impl. (4)
6. q -> w D. N. (5)
PREMISES:
(i -> e) -> c
c -> ~c
CONCLUSION:
i
PROOF
1. (i -> e) -> c PREMISE
2. c -> ~c PREMISE
3. (i -> e) -> ~c H.S. (1, 2)
4. ~c V ~c Impl. (2)
5. ~c Tautology (4)
6. ~(i -> e) M. T. (1, 5)
7. ~(~i V e) Impl. (6)
8. ~~i & ~e D.M. (7)
9. ~~i Simp. (8)
10. i D.N. (9)
By Jesse Rappaport