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Would the cardinality of a set S = {a, b, {c, d}} be 5?

  1. Feb 18, 2010 #1
    Would the cardinality of a set S = {a, b, {c, d}} be 5?
     
  2. jcsd
  3. Feb 18, 2010 #2
    Re: Cardinality

    No, 3. The elements of the set are a, b, and {c,d}.
     
  4. Feb 18, 2010 #3
    Re: Cardinality

    But let us say that H = {c,d}. Then S = {a, b, H}. Shouldn't it be so that if H ⊂ S, c ϵ H, and d ϵ H, then c ϵ S and d ϵ S...which would mean that you could pull out more than 3 elements out of S (unless it is improper to associate elements of a particular element of a set to that set).
     
    Last edited: Feb 18, 2010
  5. Feb 18, 2010 #4
    Re: Cardinality

    H ϵ S, not H ⊂ S
     
  6. Feb 18, 2010 #5
    Re: Cardinality

    I see...Thanks for the replies.
     
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