## Intersection

### Set

 context $X,Y\in\mathfrak U$ definiendum $x\in X \cap Y$ postulate $x\in X \cap Y \Leftrightarrow (x\in X\land x\in Y)$

### Discussion

$X \cap Y$ is commutative and idempotent.

The intersection and union are associative and distributive with respect to another.

#### Reference

Wikipedia: Intersection