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Using the definition of the binary product

  1. Dec 1, 2008 #1
    Prove or find counterexamples:
    If A x B = empty set then A = empty set or B = empty set.
     
  2. jcsd
  3. Dec 2, 2008 #2

    HallsofIvy

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    Well, you titled this "using the definition of the binary product"?
    So what is the definition of A x B?

    Then consider using an indirect proof: If neither A nor B is empty...
     
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