In set theory, the union of two sets ${\displaystyle A, B}$ is the set of all elements in ${\displaystyle A}$ , in ${\displaystyle B}$ , or both.

Example

Suppose ${\displaystyle A=\{w,x,y\}}$ and ${\displaystyle B=\{t,x,z\}}$ :

${\displaystyle A\cup B=\{t,w,x,y,z\}}$

See also

• Logical disjunction (equivalent in logic)
• Complement (set theory)
• Intersection (set theory)
• Symmetric difference