Set Union/Examples/Set of Arbitrary Sets

Example of Union of Set of Sets

Let:

 $\displaystyle A$ $=$ $\displaystyle \set {1, 2, 3, 4}$ $\displaystyle B$ $=$ $\displaystyle \set {a, 3, 4}$ $\displaystyle C$ $=$ $\displaystyle \set {2, a}$

Let $\mathscr S = \set {A, B, C}$.

Then:

$\displaystyle \bigcup \mathscr S = \set {1, 2, 3, 4, a}$