1. G ⊃ (H ⊃ K)
2. (H v ~M) ⊃ ~K
3. H / ~G
| 4. ~~G Assumption for Indirect Proof
| 5. G 4, Double Negation
| 6. H ⊃ K 1,5, Modus Ponens
| 7. K 6,3, Modus Ponens
| 8. H v ~M 3, Addition
| 9. ~K 2,8, Modus Ponens
|10. K & ~K 7,9, Conjunction
11. ~G Lines 4-10 for Indirect Proof
Edwin