Pearl's d-separation is a foundational notion to study conditional independence between random variables on directed acyclic graphs. Pearl defined the d-separation of two subsets conditionally on a third one. We show how the d-separation can be extended beyond acyclic graphs and can be expressed and characterized as a binary relation between vertices.

翻译：珍珠的 d 分离是一个基本概念,用于研究定向环绕图上的随机变量之间的有条件独立。 珍珠以第三个为条件定义了两个子项的 d 分离。 我们展示了 d 分离如何可以超越环绕图,并可以表达和定性为脊椎之间的二进制关系。