Casini G.; Meyer T.; Varzinczak I.
CNR-ISTI, Pisa, Italy - University of Cape Town, Cape Town, South Africa e CAIR, South Africa; CRIL, University of Cape Town, Cape Town, South Africa - CAIR, South Africa e CNR-ISTI, Pisa, Italy; CRIL, Univ. Artois & CNRS, France - Stellenbosch University, South Africa - CAIR, South Africa e CNR-ISTI, Pisa, Italy
Conditionals are useful for modelling, but aren't always sufficiently expressive for capturing information accurately. In this paper we make the case for a form of conditional that is situation-based. These conditionals are more expressive than classical conditionals, are general enough to be used in several application domains, and are able to distinguish, for example, between expectations and counterfactuals. Formally, they are shown to generalise the conditional setting in the style of Kraus, Lehmann, and Magidor. We show that situation-based conditionals can be described in terms of a set of rationality postulates. We then propose an intuitive semantics for these conditionals, and present a representation result which shows that our semantic construction corresponds exactly to the description in terms of postulates. With the semantics in place, we proceed to define a form of entailment for situated conditional knowledge bases, which we refer to as minimal closure. It is reminiscent of and, indeed, inspired by, the version of entailment for propositional conditional knowledge bases known as rational closure. Finally, we proceed to show that it is possible to reduce the computation of minimal closure to a series of propositional entailment and satisfiability checks. While this is also the case for rational closure, it is somewhat surprising that the result carries over to minimal closure.
Conditional reasoning, Non-monotonic reasoning, Counterfactual reasoning, Defeasible reasoning, Belief change
Meyer Thomas Andreas, Varzinczak Ivan, Casini Giovanni
ISTI – Istituto di scienza e tecnologie dell'informazione "Alessandro Faedo"
ID: 459191
Year: 2021
Type: Rapporto tecnico
Creation: 2021-11-19 11:41:05.000
Last update: 2022-02-14 13:07:45.000
External IDs
CNR OAI-PMH: oai:it.cnr:prodotti:459191