Definition:Quasi-Reflexive Relation/Definition 1

Definition
Let $\RR \subseteq S \times S$ be a relation in $S$.

$\RR$ is quasi-reflexive :


 * $\forall x, y \in S: \tuple {x, y} \in \RR \implies \tuple {x, x} \in \RR \land \tuple {y, y} \in \RR$

Also see

 * Equivalence of Definitions of Quasi-Reflexive Relation