9. AΔB = (A-B) ∪^ (B-A) (A-B) ∪^ (B-A)
De Morgan’s laws on complementation
- The complement of the union of any two sets is equal to the intersection of their
complements.
(A ∪ B)’ = A’ ∩^ B’
- The complement of the intersection of any two sets is equal to the union of
their complements.
(A ∩^ B)’ = A’ ∪ B’
De Morgan’s laws on set difference
- A – (B ∪^ C) = (A - B) ∩^ (A - C)
- A – ( B ∩^ C) = (A - B) ∪^ (A - C)
The idea of Venn diagram and the different laws using the Venn diagram can be
taught with the assistance of embossed diagrams of all the set notations used.A B