o be explicit, we state all d-separation rules entailed by $G_0$ and $G_0$. Both graphs entail the following sets of d-separation rules:  -   $X_0$ is d-separated from $X_0$ given $(X_0, X_0)$ or $(X_0, X_0, X_0)$.  -   $X_0$ is d-separated from $X_0$ given $(X_0, X_0)$ or $(X_0, X_0, X_0)$.  The set of d-separation rules entailed by $G_0$ which are not entailed by $G_0$ is as follows:  -   $X_0$ is d-separated from $X_0$ given $(X_0, X_0)$ or $(X_0, X_0, X_0)$.  -   $X_0$ is d-separated from $X_0$ given $(X_0, X_0)$.  Furthermore, the set of d-separation rules entailed by $G_0$ which are not entailed by $G_0$ is as follows:  -   $X_0$ is d-separated from $X_0$ given $(X_0, X_0)$.  -   $X_0$ is d-separated from $X_0$ given $