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Homework Help: Proof by contradiction

  1. Mar 1, 2009 #1
    1.the qustion is proof by contradiction is in the jpg file



    2. the format of the solution is in the attachement doc.
     

    Attached Files:

  2. jcsd
  3. Mar 1, 2009 #2

    HallsofIvy

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    The FORMAT of the solution is to be as given in that "Word" file? Since you want to prove "not a" by contradiction, start with its contradiction: "not(not a)= a". Then see what follows from "a". For example, you are given "(not d) or c implies (not a)". The contrapositive of that is "a implies not((not d) or c)" which is the same as "a implies (d and (not c)"
     
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