SOLUTION: URGENT: P. R->~Q. P->Q therefore ~R I need to write out a proof for the following problem using repetition, motus ponen, motus tollens, double negation, etc. This is not graded

Question 509899: URGENT:
P. R->~Q. P->Q therefore ~R
I need to write out a proof for the following problem using repetition, motus ponen, motus tollens, double negation, etc. This is not graded, but I'm trying to understand it and any help would be appreciated.
Answer by Edwin McCravy(20055) (Show Source): You can put this solution on YOUR website!

To prove:
P. R->~Q. P->Q therefore ~R

 P         given premise
 P->Q      given premise
----
∴Q         modus ponens
∴~~Q       double negation

  R->~Q    given premise
~~Q
-------
∴~R        modus tollens 

Edwin

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