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Math Help - Argument #4, determine validity.

  1. #1
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    Argument #4, determine validity.

    This is the one I am having the most trouble with, thanks in advance.

    Determine, by any means, whether the following argument is valid or not:

    "If a set A is a proper subset of another set B, then the intersection of A and B is also a proper subset of B; but A is equal to B or B is a proper subset of A; hence the intersection of A and B is a proper subset of A."

    Before I try using LaTex to start the problem, is the file really a whole gig...heh.
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  2. #2
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    A = (1,2,3,4) B = (2,3,4,1)

    A ^ B = (1,2,3,4) = A = B...

    valid?
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  3. #3
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    In your example, the intersection of A and B is not a proper subset of A.

    Note that set elements should be written between curly braces, not parentheses.
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  4. #4
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    Like I said before I am pretty lost, any help would be appreciated.

    My parentheses was meant to represent the squiggly lines, btw.
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  5. #5
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    but A is equal to B or B is a proper subset of A
    In your example, this is true.

    hence the intersection of A and B is a proper subset of A
    And this is false in your example.

    My parentheses was meant to represent the squiggly lines, btw.
    Then why not use { and } keys?
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