Observations on Darwiche and Pearl's Approach for Iterated Belief Revision

Observations on Darwiche and Pearl's Approach for Iterated Belief Revision

Theofanis Aravanis, Pavlos Peppas, Mary-Anne Williams

Proceedings of the Twenty-Eighth International Joint Conference on Artificial Intelligence
Main track. Pages 1509-1515. https://doi.org/10.24963/ijcai.2019/209

Notwithstanding the extensive work on iterated belief revision, there is, still, no fully satisfactory solution within the classical AGM paradigm. The seminal work of Darwiche and Pearl (DP approach, for short) remains the most dominant, despite its well-documented shortcomings. In this article, we make further observations on the DP approach. Firstly, we prove that the DP postulates are, in a strong sense, inconsistent with Parikh's relevance-sensitive axiom (P), extending previous initial conflicts. Immediate consequences of this result are that an entire class of intuitive revision operators, which includes Dalal's operator, violates the DP postulates, as well as that the Independence postulate and Spohn's conditionalization are inconsistent with (P). Lastly, we show that the DP postulates allow for more revision polices than the ones that can be captured by identifying belief states with total preorders over possible worlds, a fact implying that a preference ordering (over possible worlds) is an insufficient representation for a belief state.
Keywords:
Knowledge Representation and Reasoning: Belief Change
Knowledge Representation and Reasoning: Reasoning about Knowlege and Belief