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Homework Help: Question on rules of inference

  1. Sep 13, 2010 #1
    1. The problem statement, all variables and given/known data
    What rule of inference is used with the following statement:
    Kangaroos live in Australia and are marsupials. Therefore, kangaroos are marsupials.

    I set this up as p = kangaroos live in Australia and q = kangaroos are marsupials. Therefore, p. To me, it looks like the "simplification" rule, but in our book, simplification is set up as:
    p ^ q; therefore, p. Can I change how I defined p and q or am I wrong to begin with?
  2. jcsd
  3. Sep 13, 2010 #2


    Staff: Mentor

    Therefore q.
    If your hypothesis is p ^ q, the conclusion can be p or it can be q.

    p ^ q ==> q
    p ^ q ==> p
  4. Sep 13, 2010 #3
    Thank you.
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