Question 387959
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1.  (S v T) &#8835; (S &#8835; ~T)
2.  (S &#8835; ~T) &#8835; (T &#8835; K)
3.  S v T                              /S v K
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4.  S &#8835; ~T                     1,3  Modus Ponens
5.  T &#8835; K                      2,4  Modus Ponens
6.  ~~S v T                3    Double Negation
7.  ~S &#8835; T                     6    Material Implication
8.  ~S &#8835; K               7,5  Hypothetical Syllogism
9.  ~~S v K                8    Material Implication
10. S v K                  9    Double Negation
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