Fundamenta Informaticae - Volume 15, issue 3-4

Article Type: Other

DOI: 10.3233/FI-1991-153-401

Citation: Fundamenta Informaticae, vol. 15, no. 3-4, pp. i-vi, 1991

Authors: Ras, Zbigniew W.

Article Type: Editorial

DOI: 10.3233/FI-1991-153-402

Citation: Fundamenta Informaticae, vol. 15, no. 3-4, pp. 209-210, 1991

Authors: Dubois, Didier | Lang, Jérôme | Prade, Henri

Article Type: Research Article

Abstract: This paper is an attempt to cast both uncertainty and time in a logical framework. It generalizes possibilistic logic, previously developed by the authors, where each classical formula is associated with a weight which obeys the laws of possibility theory. In the possibilistic temporal logic we present here, each formula is associated with a time set (a fuzzy set in the more general case) which represents the set of instants where the formula is certainly true (more or less certainly true in the general case). When a particular instant is fixed we recover possibilistic logic. Timed possibilistic logic generalizes possibilistic …logic also in the sense that we substitute the lattice structure of the set of the (fuzzy) subsets of the temporal scale to the lattice structure underlying the certainty weights in possibilistic logic. Thus many results from possibilistic logic can be straightforwardly generalized to timed possibilistic logic. Illustrative examples are given. Show more

DOI: 10.3233/FI-1991-153-403

Citation: Fundamenta Informaticae, vol. 15, no. 3-4, pp. 211-234, 1991

Authors: Fitting, Melvin C.

Article Type: Research Article

Abstract: Two families of many-valued modal logics are investigated. Semantically, one family is characterized using Kripke models that allow formulas to take values in a finite many-valued logic, at each possible world. The second family generalizes this to allow the accessibility relation between worlds also to be many-valued. Gentzen sequent calculi are given for both versions, and soundness and completeness are established.

DOI: 10.3233/FI-1991-153-404

Citation: Fundamenta Informaticae, vol. 15, no. 3-4, pp. 235-254, 1991

Authors: Parikh, Rohit

Article Type: Research Article

Abstract: We study monotonic and non-monotonic Logics of Knowledge, giving decision procedures and completeness results. In particular we develop a model theory for a non-monotonic Logic of Knowledge and show that it corresponds exactly to normal applications of a non-monotonic rule of inference due to McCarthy.

DOI: 10.3233/FI-1991-153-405

Citation: Fundamenta Informaticae, vol. 15, no. 3-4, pp. 255-274, 1991

Authors: Konolige, Kurt

Article Type: Research Article

Abstract: Quantification in modal logic is interesting from a technical and philosophical standpoint. Here we look at quantification in autoepistemic logic, which is a modal logic of self-knowledge. We propose several different semantics, all based on the idea that having beliefs about an individual amounts to having a belief using a certain type of name for the individual.

DOI: 10.3233/FI-1991-153-406

Citation: Fundamenta Informaticae, vol. 15, no. 3-4, pp. 275-300, 1991

Authors: Horty, John F. | Thomason, Richmond H.

Article Type: Research Article

DOI: 10.3233/FI-1991-153-407

Citation: Fundamenta Informaticae, vol. 15, no. 3-4, pp. 301-323, 1991

Authors: Kraus, Sarit | Perlis, Donald | Horty, John

Article Type: Research Article

DOI: 10.3233/FI-1991-153-408

Citation: Fundamenta Informaticae, vol. 15, no. 3-4, pp. 325-332, 1991

Authors: Maida, Anthony S. | Wainer, Jacques | Cho, Sehyeong

Article Type: Research Article

Abstract: This paper explores the task of belief reasoning in light of the more basic cognitive principles of introspection and analogy-based reasoning. Using a syntactic framework, we show in detail how the ability to conduct belief reasoning can be reduced to principles of introspection and analogy-based reasoning.

DOI: 10.3233/FI-1991-153-409

Citation: Fundamenta Informaticae, vol. 15, no. 3-4, pp. 333-356, 1991

Authors: Huynh, Tien | Joskowicz, Leo | Lassez, Catherine | Lassez, Jean-Louis

Article Type: Research Article

Abstract: We address the problem of building intelligent systems to reason about linear arithmetic constraints. We develop, along the lines of Logic Programming, a unifying framework based on the concept of Parametric Queries and a quasi-dual generalization of the classical Linear Programming optimization problem. Variable (quantifier) elimination is the key underlying operation which provides an oracle to answer all queries and plays a role similar to Resolution in Logic Programming. We discuss three methods for variable elimination, compare their feasibility, and establish their applicability. We then address practical issues of solvability and canonical representation, as well as dynamical updates and feedback. …In particular, we show how the quasi-dual formulation can be used to achieve the discriminating characteristics of the classical Fourier algorithm regarding solvability, detection of implicit equalities and, in case of unsolvability, the detection of minimal unsolvable subsets. We illustrate the relevance of our approach with examples from the domain of spatial reasoning and demonstrate its viability with empirical results from two practical applications: computation of canonical forms and convex hull construction. Show more

DOI: 10.3233/FI-1991-153-410

Citation: Fundamenta Informaticae, vol. 15, no. 3-4, pp. 357-379, 1991