Discrete Math

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Justifying your conclusions (you could also use examples in order to illustrate your results).

What can you say about the sets A and B if we know that:

1. A ∪ B = A
2. A ∩ B = A

Thanks for any helpful replies :)

  • Discrete Math -

    1. A∪B = A
    => x∈B -> x∈A
    => B⊆A

    2. A∩B = A
    => x∈A -> x∈B
    => A⊆B

    Now
    B⊆A ∧ A⊆B
    means what?

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