Unified semantics for revision and update, or the theory of lazy update
1995, Trabajos de las 24 Jornadas Argentinas de Informática e Investigación …, 1995Citas: 8
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Autor(es)
Verónica Becher
Abstract
This paper deals with the connection between two formalisms for theory change: the AGM model of revision and the Katsuno-Mendelzon model of update. Revision and update have been considered orthogonal operations serving different purposes. However, there have been no attempts of recasting one function in terms of the other one, and this is what this work addresses. We semantically recast the AGM revision function as a special case of update. The strategy is to define a global notion of distance (from the theory under update) in terms of the indexical orderings of comparative similarity. We show that the change-operation entailed by this global distance is precisely an AGM revision function. This result allows for conclusions about the two fundamentally different forms of theory change.