Question 1194062
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1:  X V Y

2:  Z -> X

3:  (Y & ~Z) -> (W & ~Z)

4:  ~X                     |  W

5:  Y                      1, 4  Disjunctive Syllogism

6:  ~Z                     2, 4  Modus Tollens

7:  Y & ~Z                 5, 6  Conjunction

8:  W & ~Z                 3, 7  Modus Ponens

9:  ⸫ W                    8     Simplification


</pre>

																
John
*[tex \LARGE e^{i\pi}\ +\ 1\ =\ 0]
My calculator said it, I believe it, that settles it
*[illustration darwinfish.jpg]

From <https://www.algebra.com/cgi-bin/upload-illustration.mpl> 
I > Ø
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