Integrating semantic inference in a probabilistic approach to information retrieval. II

For pt. I see Proc. of ICCI 1992 Conf. (1992). Semantic-based approaches and probabilistic approaches are actually used in information retrieval separately. Their integration allows the semantic-based approach to be endowed with a well-founded theoretic background, and the probabilistic approach to be evaluated with semantic consideration. The paper demonstrates that such an integration is sound theoretically. Using several concepts developed in the study of subjunctive conditionals, a modal logic model is proposed which is capable of describing the approach suggested in part I, and it is proved to be a probabilistic model