Question 869969
<pre>
1. D v C
2. C > (F v D)
3. ~F
conclusion: D
-------------------------------------------------------
4.  ~~C > (F v D)                                  2      Double Negation
5.  ~C v (F v D)                                   4      Material Implication
6.  ~C v (D v F)                                   5      Commutation
7.  (~C v D) v F                                   6      Association
8.  (C > D) v F                                    7      Material Implication
9.  F v (C > D)                                    8      Commutation                                    
10. ~~F v (C > D)                                  9      Double Negation
11. C > D                                          10,3   Disjunctive Syllogism
12. ~~D v C                                        1      Double Negation
13. ~D > C                                         12     Material Implication
14. ~D > D                                         13,11  Hypothetical Syllogism
15. ~~D v D                                        14     Material Implication
16. D v D                                          15     Double Negation
17. D                                              16     Tautology
</pre>