1.  A -> (C V B)
2.  ~(D V C)
3.  ~(E V B)      /∴ ~A 

               | 4. ~~A            AIP 
               | 5.  A           4, DN
               | 6. C V B        1,5, MP        
               | 7. ~D & ~C      2, DM
               | 8. ~E & ~B      3, DM
               | 9. ~B & ~E      8, comm.
               |10. ~B           9, simp.
               |11. B V C        6, comm.
               |12. C           11,10, DS
               |13. ~C & ~D      7, comm.
               |14. ~C          13, simp.
               |15. C & ~C      12,14 conj
16. ~A                           4-15 IP

Edwin