$A = \setdef{1, 2}$ and $B = \setdef{3, 4}$
Terms
| Term | This example | Why |
|---|---|---|
| union | $A \cup B = \setdef{1, 2, 3, 4}$ | |
| intersection | $A \cap B = \emptyset$ | $A$ and $B$ have no elements in common, so their intersection is empty, and removing $B$ from $A$ changes nothing. |
| set difference | $A \setminus B = \setdef{1, 2}$ | |
| disjoint union (of disjoint sets) | $A \cup B = \setdef{1, 2, 3, 4}$ |