Definition 5.36 (Relations)

#Definition

Let $A$ be a set. A $relation on the set A$ is a relation from $A$ to itself.

Example

Let $A : = {1, 2, 3, 4}$
Which pairs are in the relation $R$ on $A$ , given by $R : = {(a, b) | a divides b}$ ?

The relation $R$ can be represented both $graphically$ and by an $adjacency matrix$

#TODO Continue example