 The inferential nature of the condition that a cause must be a ranking-theoretic reason for its effect can also be seen from the following two results. First, the conditionalization of a belief function \(\beta\) defines a belief revision scheme (Spohn 1988). Such a scheme tells us how a rational agent should change his or her beliefs in light of new information (Gärdenfors 1988). Second, any belief revision scheme—in the sense of the AGM theory by Alchourrón, Gärdenfors, and Makinson (1985)—defines a nonmonotonic and enthymematic inference relation (Gärdenfors 1991). This result motivates the above definition of the inference relation \(A \infd_\kappa B\).