Laws of Set Algebra
From the given Venn diagram where T is the universal set and A its subset that we can deduce a number of laws as:
i. A υ Ø = A
ii. A υ T = T
iii. A υ A = A
iv. A ∩ A = A
v. A ∩ T = A
vi. A υ A^{1} = T
vii. A υ A^{1} = Ø
viii. (A^{1})^{1} = A