1. (C v R) ⊃ (N • I)
2. (N v P) ⊃ (I ⊃ ~C) /~C
| 3. ~~C AIP
| 4. C 3, double negation
| 5. C v R 4, addition
| 6. N • I 1,5, modus ponens
| 7. N 6, simplification
| 8. N v P 7, addition
| 9. I ⊃ ~C 2,8, modus ponens
|10. I • N 6, commutation
|11. I 10, simplification
|12. ~C 9,11, modus ponens
|13. C • ~C 4,12, conjunction
14. ~C Lines 3-13 IP
Edwin