ON THE USE OF EPISTEMIC ORDERING FUNCTIONS AS DECISION CRITERIA FOR AUTOMATED AND ASSISTED BELIEF REVISION IN SNEPS
A. Fogel, Ari Fogel · ProQuest Demo Repository · 2011
In this thesis I implement belief revision in SNePS based on a user-supplied epistemic ordering of propositions. I provide a decision procedure that performs revision completely automatically when given a well preorder. I also provide a decision procedure that, when given a total preorder, performs revision with a minimal number of queries to the user when multiple propositions within a minimally-inconsistent set are minimally epistemically entrenched. These procedures are implemented in SNePS as options alongside the old belief revision subsystem, wherein revision must be done entirely by hand. I implement both prioritized and nonprioritized belief revision by adjusting the epistemic ordering function passed to the new procedures. The first procedure uses O(|Σ|) units of space, and completes within O(|Σ|² · smax) units of time, where Σ is the set of distinct minimally-inconsistent sets, and smax is the number of propositions in the largest minimally-inconsistent set. The second procedure uses O(|Σ|² · [special characters omitted]) space and O(|Σ|² · [special characters omitted]) time. The examples provided herein demonstrate that the new procedures generalize previous work on belief revision in SNePS.