Question 973427
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1. (O+M)>S
2. ~S     /~M

3. ~S>~(O+M)      1, Contrapositive
4. ~S>(~O•~M)     3, DeMorgan's law
5. ~O•~M        4,2, Modus Ponens
6. ~M             5, Simplification

Edwin</pre>