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Help Denumerability

  1. Mar 17, 2008 #1
    Would someone please help me on the topic of Denumerability.

    Prove that if A and B are disjoint denumerable sets then A union B is denumerable.
  2. jcsd
  3. Mar 17, 2008 #2
    Welcome to PF!

    How would you state the definition of denumerability?
  4. Mar 17, 2008 #3


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    A and B being denumerable means there is are complete lists of the form:

    a1, a2, a3,.... for A
    b1, b2, b3,.... for B

    The union can be listed as:

    a1, b1, a2, b2, a3, b3, .......
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