Sets priority
- Roster
{1,2,3}· builder{x ∈ Z | −2 ≤ x < 3}= {−2,−1,0,1,2} A ∪ Bin either ·A ∩ Bin both ·A − Bin A not B =A ∩ B′·A′= U − A- Symmetric difference
A ⊕ B = (A−B) ∪ (B−A) - De Morgan:
(A∩B)′ = A′∪B′,(A∪B)′ = A′∩B′ |A∪B| = |A|+|B|−|A∩B||A∪B∪C| = ΣA − Σ(pairs) + |A∩B∩C|- Neither =
|U| − |A∪B| - Subsets of n-set:
2ⁿ; proper subsets2ⁿ − 1; power set size2ⁿ |A×B| = |A|·|B|, pairs are ordered (a,b)- Disjoint:
A ∩ B = ∅. ∅ is a subset of every set.