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Proving the pigeonhole directly. I'm stuck.

  1. May 5, 2009 #1
    1. The problem statement, all variables and given/known data
    Prove the pigeonhole principle directly. so basically |Nk-{x}|=|Nk-1| if k>1 is an integer and x belongs to the set of naturals.

    2. Relevant equations

    3. The attempt at a solution
    I have no idea even where to begin.
  2. jcsd
  3. May 6, 2009 #2


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    Doesn't it suffice to write down a bijection between the two sets you mentioned?
  4. May 7, 2009 #3
    Yeah I guess that would work since things are equivalent if they are a bijection. Thanks man
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