A ProbLog program is a logic program with facts that only hold with a specified probability. In this contribution, we extend this ProbLog language by the ability to answer “What if” queries. Intuitively, a ProbLog program defines a distribution by solving a system of equations in terms of mutually independent predefined Boolean random variables. In the theory of causality, Judea Pearl proposes a counterfactual reasoning for such systems of equations. Based on Pearl’s calculus, we provide a procedure for processing these counterfactual queries on ProbLog programs, together with a proof of correctness and a full implementation. Using the latter, we provide insights into the influence of different parameters on the scalability of inference. Finally, we also show that our approach is consistent with CP-logic, that is with the causal semantics for logic programs with annotated with disjunctions.

ProbLog 程序是一种逻辑程序，其中的事实仅以指定的概率成立。在此贡献中，我们通过回答“假设”查询的能力来扩展此 ProbLog 语言。直观上，ProbLog 程序通过根据相互独立的预定义布尔随机变量求解方程组来定义分布。在因果关系理论中，朱迪亚·珀尔 (Judea Pearl) 为此类方程组提出了反事实推理。基于 Pearl 的微积分，我们提供了一个在 ProbLog 程序上处理这些反事实查询的过程，以及正确性证明和完整的实现。使用后者，我们深入了解不同参数对推理可扩展性的影响。最后，我们还表明我们的方法与 CP-logic 一致，