1. (P ∨ Q) · ~R
2. ~R ⊃ (S · ~P)
3. Q ⊃ (P ∨ T) ∴ T ∨ U
4. ~R · (P ∨ Q) 1, commutation
5. ~R 4, simplification
6. S · ~P 2,5, modus ponens
7. ~P · S 6, commutation
8. ~P 7, simplification
9. P ∨ Q 1, simplification
10. Q 9,8, disjunctive syllogism
11. P ∨ T 3,10 modus ponens
12. T 11,8 disjunctive syllogism
13. T ∨ U 12, addition
Edwin