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Math Help - Another bounded proof

  1. #1
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    Another bounded proof

    Prove that if B subset A subset Real #'s and A is bounded, then B is bounded.

    Proof attempt:
    Assume B subset A subset Real #'s and A is bounded.
    Then a <= u for all a element A and l <= a for all a element A, where u is upper bound and l is lower bound.
    Since B subset A, every x element B => x element A.
    Then a <= u for all a element B and l <= a for all a element B.
    Therefore, B is bounded.

    I was wondering if this was correct, and if it is not how I can fix it if possible.
    Thanks
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  2. #2
    Grand Panjandrum
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    Quote Originally Posted by tbyou87 View Post
    Prove that if B subset A subset Real #'s and A is bounded, then B is bounded.

    Proof attempt:
    Assume B subset A subset Real #'s and A is bounded.
    Then a <= u for all a element A and l <= a for all a element A, where u is upper bound and l is lower bound.
    Since B subset A, every x element B => x element A.
    Then a <= u for all a element B and l <= a for all a element B.
    Therefore, B is bounded.

    I was wondering if this was correct, and if it is not how I can fix it if possible.
    Thanks
    It looks more or less OK to me

    RonL
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