 The most important principle connecting the causal structure on \(\bV\), as represented in a graph \(\bG\), and the probability distribution P on \(\bV\) is the Markov Condition (MC). Let us first consider the case where \(\bG\) is a DAG. Then P satisfies the Markov Condition (MC) relative to \(\bG\) if and only it satisfies these three conditions: