Many-to-One Relation/Examples

Examples of Many-to-One Relations

Square

Let $\RR \subseteq \R \times \R$ be the relation on $\R$ defined as:

$\forall \tuple {x, y} \in \R \times \R: \tuple {x, y} \in \RR \iff x^2 = y$

Then $\RR$ is a many-to-one relation