Does anyone know if this is true [itex]A \bigcap B^{c} = \emptyset

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SUMMARY

The statement "A ∩ B^c = ∅ ⇔ A ∪ B^c = U" is definitively false. A counterexample exists even within a universal set U of cardinality 3. The discussion highlights the importance of understanding set operations and their implications in set theory, particularly the relationship between intersections and unions involving complements.

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  • Familiarity with set complements, denoted as B^c.
  • Knowledge of universal sets and cardinality.
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Does anyone know if this is true [itex]A \bigcap B^{c} = \emptyset \Leftrightarrow A \bigcup B^{c} = U[/itex] ?
 
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It's obviously false. You should readily be able to find a counter example even for U being a set of cardinality 3.
 

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