# Law

## Law

Relationship or property.
Sometimes a synonym for rule.

### Examples

• Addition in the set of whole numbers is an internal composition law in $$\mathbb{N}$$.
• Division in the set of integers is not an internal composition law in $$\mathbb{N}$$ because the results obtained are not all elements of $$\mathbb{N}$$.
• The multiplication of a vector by a real number (scalar) is an external composition law with results that are vectors.