1. A -> (B -> C)
2. A -> B
3. ~C ->(A V D) / C V D
| 4. ~(C V D) AIP
| 5. ~C & ~D 4, DM
| 6. ~C 5, Simp
| 7. A V D 3,6, MP
| 8. ~D & ~C 5, Comm
| 9. ~D 8, Simp
|10. D V A 7, Comm
|11. A 10,9, DS
|12. B 2,12, MP
|13. B -> C 1,13, MP
|14. C 13,12, MP
|15. C & ~C 14,6, Conj
16. C V D 4-15 IP
Edwin