1. G · K 2. K ⊃ E 3. E ⊃ (G ⊃ H) /H 4. K · G 1, Commutation 5. K 4, Simplification 6. E 2, Modus ponens 7. G ⊃ H 3, Modus ponens 8. G 1, Simplification 9. H 7,8, Modus ponens Edwin