On the Logic of Theory Change: Contraction without Recovery

The postulate of Recovery, among the six postulates for theory contraction, formulated and studied by Alchourr´on, G¨ardenfors and Makinson is the one that has provoked most controversy. In this article we construct withdrawal functions that do not satisfy Recovery, but try to preserve minimal change, and relate these withdrawal functions with the AGM contraction functions. Key words: Theory change, AGM theory, belief contraction, recovery postulate, Levi identity, Harper identity

• Type: Journal
• Year: 1998
• Where: JOLLI
• Authors: Eduardo L. Fermé
• Keywords: AGM Contraction Functions, JOLLI 1998, Postulate, Theory Contraction