1. G v (R & E) 2. (G v E) -> ~R :. G v M ------------------------------------------ 3. (G v R) & (G v E) 1 Distribution 4. (G v E) & (G v R) 3 Commutation 5. G v R 3 Simplification 6. G v E 4 Simplification 7. ~R 2,6 Modus Ponens 8. ~~G v R 5 Double Negation 9. ~G -> R 8 Material Implication 10. G 9,7 Modus Tollens 11. G v M 10 Addition