division

Divisibility

The divisibility relation on the integers $\mathbb{Z}$ is defined as:

$$\forall a,b\in \mathbb{Z},a|b:=\exists c\in \mathbb{Z}:a\cdot c=b$$

E.g. $2|6,-2|6,17|0$, but $2\nmid 7,0\nmid 5$.