Intersection (set theory)

In set theory, the intersection of two sets $A, B$ is the set of all elements in $A$ that also belong in $B$ .

Definition
Given two sets A and B, $A \cap B = \{ x|x \in A \and x \in B \}$

If the intersection of two sets is empty, then the two sets are disjoint.

Example

Suppose $A=\{a,b,f,g\}$ and $B=\{b,c,d,g\}$ .

$A\cap B=\{b,g\}$

See also

• Logical conjuction (Equivalent in logic)
• Complement (set theory)
• Union (set theory)
• Symmetric difference