Paper: Defaults and revision in structured theories (at LICS 1991)
Authors: Mark RyanAbstract
Starting from a logic which specifies how to make deductions from a set of sentences (a flat theory), a way to generalize this to a partially ordered bag of sentences (a structured theory) is given. The partial order is used to resolve conflicts. If φ occurs below ψ, then ψ is accepted only insofar as it does not conflict with φ. The study starts with a language L, a set of interpretations M and a satisfaction relation. The key idea is to define, for each structured theory, a preorder on interpretations. Models of the structured theory are defined to be maximal interpretations in the ordering. A revision operator that takes a structured theory and a sentence and returns a structured theory is defined. The consequence relation has the properties of weak monotonicity, weak cut, and weak reflexivity with respect to this operator, but fails their strong counterparts
BibTeX
@InProceedings{Ryan-Defaultsandrevision, author = {Mark Ryan}, title = {Defaults and revision in structured theories}, booktitle = {Proceedings of the Sixth Annual IEEE Symp. on Logic in Computer Science, {LICS} 1991}, year = 1991, editor = {Giles Kahn}, month = {July}, pages = {362--373}, location = {Amsterdam, The Netherlands}, publisher = {IEEE Computer Society Press} }