Absorption Laws (Set Theory)/Union with Intersection

Theorem

 * $S \cup \left({S \cap T}\right) = S$

Also see
$S \cup \left ({S \cap T}\right)$ is also equal to $S \cap \left ({S \cup T}\right)$:

See Absorption Laws (Set Theory): Intersection with Union.

These two results together are known as the Absorption Laws, corresponding to the equivalent results in logic.