Definition:Relation/Truth Set

Definition
Let $S \times T$ be the cartesian product of two sets $S$ and $T$. Let $\mathcal R$ be a relation on $S \times T$.

The truth set of $\mathcal R$ is the set of all ordered pairs $\left({s, t}\right)$ of $S \times T$ such that $s \mathrel{\mathcal R} t$:
 * $\mathcal T \left({\mathcal R}\right) = \left\{ {\left({s, t}\right): s \mathrel {\mathcal R} t}\right\}$

Also known as
The truth set of a relation is sometimes seen referred to as its graph.

However, this term is most usually seen in the context of a mapping.