1. (P ∨ Q) ⊃ R
2. S ⊃ ~R
3. S ∨ P / Q ⊃ P
| 4. Q Assumption for Conditional Proof
| 5. Q ∨ P 4, Addition
| 6. P ∨ Q 5, Commutation
| 7. R 6,1 Modus ponens
| 8. ~~R ⊃ ~S 2, Transposition
| 9. R ⊃ ~S 8, Double negation
|10. ~S 9,7 Modus ponens
|11. P 3,10 Disjunctive syllogism
12. Q ⊃ P lines 4-11 Conditional proof
Edwin
