# 2: Sets, Functions, and Relations

- Page ID
- 6721

- 2.2: The Boolean Algebra of Sets
- It is clear that set theory is closely related to logic. The intersection and union of sets can be defined in terms of the logical “and” and logical “or” operators. The notation {x|P(x)} makes it possible to use predicates to specify sets. And if A is any set, then the formula x∈A defines a one place predicate that is true for an entity x if and only if x is a member of A. So it should not be a surprise that many of the rules of logic have analogs in set theory.