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For the property $x \in S$ and $s \mathrel{R} y$$x \mathrel{R} y$ imply $y \in S$, I would say that $S$ is saturated by $R$. Thus, in your case, saturated by $R^{-1}$ might be an option.
For the property $x \in S$ and $s \mathrel{R} y$ imply $y \in S$, I would say that $S$ is saturated by $R$. Thus, in your case, saturated by $R^{-1}$ might be an option.
For the property $x \in S$ and $x \mathrel{R} y$ imply $y \in S$, I would say that $S$ is saturated by $R$. Thus, in your case, saturated by $R^{-1}$ might be an option.
For the property $x \in S$ and $s \mathrel{R} y$ imply $y \in S$, I would say that $S$ is saturated by $R$. Thus, in your case, saturated by $R^{-1}$ might be an option.