1. A⊃B
2. B⊃~A
3. (AvD)vE
4. (DvE)->F / F
5. Av(DvE) 3, association
6. (DvE)vA 5, commutation
|7. ~F Assumption for Indirect Proof
|8. ~(DvE) 4,7, Modus Tollens
|9. A 6,8, Disjunctive Syllogism
|10. B 1,9, Modus Ponens
|11. ~A 2,10, Modus Ponens
|12. A&~A 9,11, Conjunction
13. F Lines 7-12 Indirect Proof
Edwin