Reflexive Closure

The reflexive closure of a binary Relation $R$ on a Set $X$ is the minimal Reflexive Relation $R'$ on $X$ that contains $R$. Thus $a R' a$ for every element $a$ of $X$ and $a R' b$ for distinct elements $a$ and $b$, provided that $a R b$.

See also Reflexive Reduction, Reflexive Relation, Relation, Transitive Closure