A revision algorithm is a learning algorithm that identifies the target concept, starting from an initial concept. Such an algorithm is considered efficient if its complexity (in terms of the resource one is interested in) is polynomial in the syntactic distance between the initial and the target concept, but only polylogarithmic in the number of variables in the universe. We give efficient rev...

The theory of belief revision developed by GG ar-denfors and his colleagues characterizes the classes of reasonable belief revision operations. However, some of the assumptions made in the theory of belief revision are unrealistic from a computational point of view. We address this problem by considering revision operations that are based on a priority ordering over a set of sentences represent...

The aim of this paper is to extend the system of belief revision developed by Alchourr on, G ardenfors and Makinson (AGM) to a more general framework. This extension not only enables a treatment of revision by single sentences but also by any sets of sentences, especially by in nite sets. The extended revision and contraction operators will be called general ones, respectively. A group of post...

We present different constructions for non-prioritized belief revision, that is, belief changes in which the input sentences are not always accepted. First, we present the concept of explanation in a deductive way. Second, we define multiple revision operators with respect to sets of sentences (representing explanations), giving representation theorems. Finally, we relate the formulated operato...

This study examines the problem of belief revision, defined as deciding which of several initially accepted sentences to disbelieve, when new information presents a logical inconsistency with the initial set. In the first three experiments , the initial sentence set included a conditional sentence, a non-conditional (ground) sentence, and an inferred conclusion drawn from the first two. The new...

A general method is provided whereby bizarre revisions of consistent theories with respect to contingent sentences that they refute can be delivered by revision-functions satisfying both the basic and the supplementary postulates of the y4GM-theory of theory-revision. ?