Question 1026581
<pre>
I won't waste time with trivial 'double negation' 
and 'commutation'.

1. A -> ~(BvC)
2. ~D -> (~A->~E)
3. ~(~EvF)
4. ~F->(A->B)   	/D 

5. ~(~A->~E)->D       2, Transposition
6. ~(Av~E)->D         5, Material Implication
7. (~A&E)->D          6, DeMorgan's Law
8. E&~F               3, DeMorgan's law
9. ~F                 8, Simplification
10. A->B              4,9, Modus ponens
11. A->(~B&~C)        1, DeMorgan's law
12. A->~B             11, Simplification
13. (A->B)&(A->~B)    10,12, Conjunction of premises
14. ~A                13, Negative introduction
15. E                 8, Simplification
16. ~A&E              14,15, Conjunction of premises
17. D                 7,16, Modus ponens    

Edwin</pre>