On the logic of causal explanation

摘要

The McCain-Turner semantics of causal rules is based on a fixpoint construction similar to the one found in the definition of default logic. In the special case when the heads of the rules are literals, it can be equivalently expressed by a translation from sets of rules into sets of propositional formulas. We define a translation from causal logic into classical logic that characterizes the semantics of arbitrary causal rules, without any restrictions on their syntactic form. This translation suggests a way to extend the McCain-Turner logic to nonpropositional causal theories.