A∩B=∅A B
Ω = {1,2,...,6}A
3B≤2
∪ ∩
(A∪B) = A∩B, (A∩B) = A∪B
A∪B=B∪A, A ∩B=B∩A
∪ ∩
A∪(B∩C)=(A∪B)∩(A∪C), A∩(B∪C) = (A∩B)∪(A∩C)
A∪∅=A, A ∩∅=∅, A ∪Ω = Ω, A ∩Ω = A
(A1, . . . , An)
∀i, j ∈ {1,2, . . . , n}i6=j Ai∩Aj=∅
Sn
i=1 Ai= Ω
Ai
Ω = {1,2,...,100}A={1,2,...,20}
B={21,...,50}C={51,...,100}(A, B, C)
Ω