Question 1005915
Construct proofs to show the following are valid:
<pre>
1. ~E
2. F->(DvE)
3. ~D                :. ~F

4. ~D*~E             3,1, Conjunction
5. ~(DvE)              4, DeMorgan
6. ~(DvE)->~F          2, Transposition
7. ~F                6,5, Modus ponens
 


ALSO

 1. Z->(U*X)
 2. ~[(U*W)]
 3. W                 :. ~Z

 4. ~Uv~W               2, DeMorgan
 5. ~Wv~U               4, commutativity
 6. ~~W                 3, double negation
 7. ~U                5,6, disjunctive syllogism
 8. ~Uv~X               7, addition
 9. ~(U*X)->~Z          1, transposition
10. (~Uv~X)->~Z         9, DeMorgan
11. ~Z               10,8, modus ponens

Edwin</pre>