1. (G -> H) -> J :. H -> J -------------------------------------- 2. (~G v H) -> J 1 Material Implication 3. ~(~G v H) v J 2 Material Implication 4. (~~G * ~H) v J 3 De Morgan's Law 5. (G * ~H) v J 4 Double Negation 6. J v (G * ~H) 5 Commutation 7. (J v G) * (J v ~H) 6 Distribution 8. (J v ~H) * (J v G) 7 Commutation 9. J v ~H 8 Simplification 10. ~H v J 9 Commutation 11. H -> J 10 Material Implication