Doxastic Document Retrieval by Means of Possible-Worlds Models

Abstract

Logical models for document retrieval are theoretically reformulated as possible-worlds models from the point of view of restriction over a set of possibilities using evidence. The restriction can be regarded as crisp evidence and so the models can be further extended to belief models by means of logic of belief based on evidence. Then, nonmonotonic reasoning is shown to be implicit in indexing in logicl retrieval.