Default logic is a prominent rigorous method for reasoning with incomplete information based on assumptions. It is a static reasoning approach, in the sense that it doesn't reason about changes and their consequences. On the other hand, its nonmonotonic behaviour appears when changes to a default theory are made. This paper studies the dynamic behaviour of default logic in the face of changes. ...

This paper starts by discussing Nelson’s philosophy of mathematics, which is a blend of mathematical formalism and a radical constructivism. As such, it makes strong assertions about the foundations of mathematic and the reality of mathematical objects. We then offer our own suggestions for the definition of mathematics and the nature of mathematical reality. We suggest a second characterizatio...

Human-level AI will be achieved, but new ideas are almost certainly needed, so a date cannot be reliably predicted—maybe five years, maybe five hundred years. I’d be inclined to bet on this 21st century. It is not surprising that human-level AI has proved difficult and progress has been slow—though there has been important progress. The slowness and the demand to exploit what has been discovere...

Reasoning about causation in fact is an essential element of attributing legal responsibility. Therefore, the automation of the attribution of legal responsibility requires a modelling effort aimed at the following: a thorough understanding of the relation between the legal concepts of responsibility and of causation in fact; a thorough understanding of the relation between causation in fact an...

The construction of a concept map consists of enumerating a list of concepts and —a more difficult task— determining the linking phrases that should connect the concepts to form meaningful propositions. Appropriate word selection, both for concepts and linking phrases, is key for an accurate knowledge representation of the user’s understanding of the domain. We present an algorithm that uses Wo...

Multimedia-based ontology construction and reasoning have recently been recognized as two important issues in video search, particularly for bridging semantic gap. The lack of coincidence between low-level features and user expectation makes conceptbased ontology reasoning an attractive mid-level framework for interpreting highlevel semantics. In this report, we propose a novel model, namely on...

Syllogistic reasoning lies at the intriguing intersection of natural and formal reasoning, of language and logic. Syllogisms comprise a formal system of reasoning yet use natural language quantifiers, and invite natural language conclusions. How can we make sense of the interplay between logic and language? We develop a computational-level theory that considers reasoning over concrete situation...

Recently, Lakemeyer and Levesque proposed a logic of onlyknowing which precisely captures three forms of nonmonotonic reasoning: Moore’s Autoepistemic Logic, Konolige’s variant based on moderately grounded expansions, and Reiter’s default logic. Defaults have a uniform representation under all three interpretations in the new logic. Moreover, the logic itself is monotonic, that is, nonmonotonic...

We introduce a family of preferential consequence relations, deened by a simple and natural many-valued semantics. These relations share many desirable properties for common-sense reasoning, such as paraconsistency