Question 1156052
<pre>
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</pre>