Question 227929
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1.   P
2.   Q v R
3.   ~R v S
4.   ~Q                 / P & S
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5.   R                          2,4    Disjunctive Syllogism
6.   ~~R                          5    Double Negation
7.   S                          3,6    Disjunctive Syllogism  
8.   P & S                      1,7    Conjunction
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