1. (J > O) > ~N
2. N v [~N > (E > N)]
3. ~E > [E v (N v ~O)]
4. J > U
Conclusion: ~O
Can anybody please finish this proof for me? I'm lost.
Im pretty sure the U in 4 should be O, because U does not
appear anywhere else, so if it were J > U, it might as well have
been eliminated, as it could play no possible role in the
proof. So I am going to assume the U is a typo and should
be O instead. Then the proof is fairly straight-forward.
1. (J > O) > ~N
2. N v [~N > (E > N)]
3. ~E > [E v (N v ~O)]
4. J > O
Conclusion: ~O
5. ~N 1,4, MP
6. ~N > (E > N) 2,5, DS
7. E > N 6,5, MP
8. ~E 7,5, MT
9. E v (N v ~O) 3,8, MP
10. N v ~O 9,8, DS
11. ~O 10,5, DS
Edwin