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Math Help - Proofs involving sets and their compliments

  1. #1
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    Post Proofs involving sets and their compliments

    Prove that A is a subset of B iff B' is subset of A'
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    is up to his old tricks again! Jhevon's Avatar
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    Quote Originally Posted by instrument.santosh View Post
    Prove that A is a subset of B iff B' is subset of A'
    i would prove both direction via a direct proof

    so to start you off


    (=>) Assume A \subseteq B. Then, x \in A \implies x \in B. Now, let y \in B' .....(you want to show that this implies y \in A')

    (<=) For the converse, assume B' \subseteq A'. Then x \in B' \implies x \in A'. Now, let y \in A.....(you want to show that this implies y \in B)

    now continue
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