Definition:Many-to-One Relation/Defined/Element

Definition

Let $f \subseteq S \times T$ be a many-to-one relation.

Let $s \in S$.

Then $f$ is defined at $s$ if and only if $s \in \Dom f$, the domain of $f$.

Sources

• 1989: George S. Boolos and Richard C. Jeffrey: Computability and Logic (3rd ed.) ... (previous) ... (next): $1$ Enumerability