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Help with some set theory questions

  1. May 15, 2010 #1
    Greetings all. I was wondering if someone could give me some asistance on a few simple set theory proofs.

    1) An(B\C)=(AnB)\(AnC)
    2) A+(B+C)=(A+B)+C where + = symmetric difference
    3) If A+B = A+C then B=C
    and
    4) An(B+C) = (AnB)+(AnC)
     
  2. jcsd
  3. May 15, 2010 #2

    tiny-tim

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    Welcome to PF!

    Hi Beno! Greetings and welcome to PF! :wink:

    Show us what you've tried, and where you're stuck, and then we'll know how to help! :smile:
     
  4. May 15, 2010 #3
    With number 1
    An(B\C)=(AnB)\(AnC)
    I tried the following
    An(B\C) = An(BnC') =(AnB)n(AnC') but this was as far as it seemed to go.

    As for the others I think I've worked them out since posting
     
  5. May 15, 2010 #4

    tiny-tim

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    ok, let's do some reverse engineering :wink:

    the last step but one is going to be (AnB)n(AnC)' …

    work backwards from there. :smile:
     
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