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LICS
1991
IEEE

Defaults and Revision in Structured Theories

13 years 7 months ago
Defaults and Revision in Structured Theories
Starting from a logic which speci es how to make deductions from a set of sentences (a ` at theory'), a way to generalise this toa partiallyordered bag ofsentences (a `structured theory') is given. The partial order is used to resolve con icts. If occurs below then is accepted only insofar as it does not con ict with . We start with a language L, a set of interpretations M and a satisfaction relation M L. The key idea is to de ne, for each structured theory, a pre-order on interpretations. Models of the structured theory are de ned to be maximal interpretations in the ordering. They are shown to exist if the logic hL;M; i is compact. A revision operator is de ned, which takes a structured theory and a sentence and returns a structured theory. The consequence relation has the properties of weak monotonicity,weak cut and weak re exivity with respect to this operator, but fails their strong counterparts.
Mark Ryan
Added 27 Aug 2010
Updated 27 Aug 2010
Type Conference
Year 1991
Where LICS
Authors Mark Ryan
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