Set Formula

• A - A = Ø
• A⋂ Ø = Ø
• U ⋂ A = A
• A ∪ Ø = A
• U ∪ A = U
• B - A = B⋂ A'
• B - A = B - (A⋂B)
• (A - B) = A if A⋂B = Ø
• (A - B) ⋂ C = (A⋂ C) - (B⋂C)
• A ΔB = (A-B) U (B- A)
• n(AUB) = n(A - B) + n(B - A) + n(A⋂B)
• n(A - B) = n(A∪B) - n(B)
• n(A - B) = n(A) - n(A⋂B)
• n(A') = n(∪) - n(A)
• n(U) = n(A) + n(B) + - n(A⋂B) + n((A∪B)')
• n((A∪B)') = n(U) + n(A⋂B) - n(A) - n(B)