Results 1  10
of
29
Nonmonotonic Reasoning, Preferential Models and Cumulative Logics
, 1990
"... Many systems that exhibit nonmonotonic behavior have been described and studied already in the literature. The general notion of nonmonotonic reasoning, though, has almost always been described only negatively, by the property it does not enjoy, i.e. monotonicity. We study here general patterns of ..."
Abstract

Cited by 538 (13 self)
 Add to MetaCart
Many systems that exhibit nonmonotonic behavior have been described and studied already in the literature. The general notion of nonmonotonic reasoning, though, has almost always been described only negatively, by the property it does not enjoy, i.e. monotonicity. We study here general patterns of nonmonotonic reasoning and try to isolate properties that could help us map the field of nonmonotonic reasoning by reference to positive properties. We concentrate on a number of families of nonmonotonic consequence relations, defined in the style of Gentzen [13]. Both prooftheoretic and semantic points of view are developed in parallel. The former point of view was pioneered by D. Gabbay in [10], while the latter has been advocated by Y. Shoham in [38]. Five such families are defined and characterized by representation theorems, relating the two points of view. One of the families of interest, that of preferential relations, turns out to have been studied by E. Adams in [2]. The pr...
Dynamic Logic for Belief Revision
 Journal of Applied NonClassic Logics
"... ABSTRACT. We show how belief revision can be treated systematically in the format of dynamicepistemic logic, when operators of conditional belief are added. The core engine consists of definable update rules for changing plausibility relations between worlds, which have been proposed independently i ..."
Abstract

Cited by 41 (11 self)
 Add to MetaCart
ABSTRACT. We show how belief revision can be treated systematically in the format of dynamicepistemic logic, when operators of conditional belief are added. The core engine consists of definable update rules for changing plausibility relations between worlds, which have been proposed independently in the dynamicepistemic literature on preference change. Our analysis yields two new types of modal result. First, we obtain complete logics for concrete mechanisms postulates for belief revision can be analyzed by standard modal frame correspondences for modelchanging operations.
On the Complexity of Conditional Logics
 In Principles of Knowledge Representation and Reasoning: Proc. Fourth International Conference (KR '94
, 1994
"... Conditional logics, introduced by Lewis and Stalnaker, have been utilized in artificial intelligence to capture a broad range of phenomena. In this paper we examine the complexity of several variants discussed in the literature. We show that, in general, deciding satisfiability is PSPACEcomplete fo ..."
Abstract

Cited by 35 (5 self)
 Add to MetaCart
Conditional logics, introduced by Lewis and Stalnaker, have been utilized in artificial intelligence to capture a broad range of phenomena. In this paper we examine the complexity of several variants discussed in the literature. We show that, in general, deciding satisfiability is PSPACEcomplete for formulas with arbitrary conditional nesting and NPcomplete for formulas with bounded nesting of conditionals. However, we provide several exceptions to this rule. Of particular note are results showing that (a) when assuming uniformity (i.e., that all worlds agree on what worlds are possible), the decision problem becomes EXPTIMEcomplete even for formulas with bounded nesting, and (b) when assuming absoluteness (i.e., that all worlds agree on all conditional statements), the decision problem is NPcomplete for formulas with arbitrary nesting. 1 INTRODUCTION The study of conditional statements of the form "If : : : then : : :" has a long history in philosophy [Sta68, Lew73, Che80, Vel8...
A modal walk through space
 JOURNAL OF APPLIED NONCLASSICAL LOGICS
, 2002
"... We investigate the major mathematical theories of space from a modal standpoint: topology, affine geometry, metric geometry, and vector algebra. This allows us to see new finestructure in spatial patterns which suggests analogies across these mathematical theories in terms of modal, temporal, and ..."
Abstract

Cited by 31 (5 self)
 Add to MetaCart
We investigate the major mathematical theories of space from a modal standpoint: topology, affine geometry, metric geometry, and vector algebra. This allows us to see new finestructure in spatial patterns which suggests analogies across these mathematical theories in terms of modal, temporal, and conditional logics. Throughout the modal walk through space, expressive power is analyzed in terms of language design, bisimulations, and correspondence phenomena. The result is both unification across the areas visited, and the uncovering of interesting new questions.
Explanatory Update Theory: Applications of Counterfactual Reasoning to Causation
 Artificial Intelligence
, 1999
"... A stratified view of causal reasoning is set forth; one in which the identification of counterfactual dependencies plays an important role in determining what sort of causal connection, if any, exists between two events named by a given pair of partial descriptions. A semantics for temporal counterf ..."
Abstract

Cited by 14 (6 self)
 Add to MetaCart
A stratified view of causal reasoning is set forth; one in which the identification of counterfactual dependencies plays an important role in determining what sort of causal connection, if any, exists between two events named by a given pair of partial descriptions. A semantics for temporal counterfactuals in which events are represented at the object level is then formalized based on a syntactic form of belief updating. Counterfactuals are evaluated relative to an agent's information state, taken to include a set of initial beliefs together with additional assumptions to handle the frame problem. Inertial inferences emerge as a sideeffect of requiring minimal information change between states of the world in some chronicle. A chronicle is, in addition, assumed minimal with respect to an explanatory preference that minimizes the set of beliefs that are not part of an agent's initial set of beliefs or are not supported by some body of lawlike knowledge. A number of epistemic preferenc...
Modal Logic: A Semantic Perspective
 ETHICS
, 1988
"... This chapter introduces modal logic as a tool for talking about graphs, or to use more traditional terminology, as a tool for talking about Kripke models and frames. We want the reader to gain an intuitive appreciation of this perspective, and a firm grasp of the key technical ideas (such as bisimul ..."
Abstract

Cited by 13 (1 self)
 Add to MetaCart
This chapter introduces modal logic as a tool for talking about graphs, or to use more traditional terminology, as a tool for talking about Kripke models and frames. We want the reader to gain an intuitive appreciation of this perspective, and a firm grasp of the key technical ideas (such as bisimulations) which underly it. We introduce the syntax and semantics of basic modal logic, discuss its expressivity at the level of models, examine its computational properties, and then consider what it can say at the level of frames. We then move beyond the basic modal language, examine the kinds of expressivity offered by a number of richer modal logics, and try to pin down what it is that makes them all ‘modal’. We conclude by discussing an example which brings many of the ideas we discuss into play: games.
Preference logic, conditionals, and solution concepts in games
 Krister Segerberg. University of Uppsala
, 2005
"... Preference is a basic notion in human behaviour, underlying such varied phenomena as individual rationality in the philosophy of action and game theory, obligations in deontic logic (we should aim for the best of all possible worlds), or collective decisions in social choice theory. Also, in a more ..."
Abstract

Cited by 13 (6 self)
 Add to MetaCart
Preference is a basic notion in human behaviour, underlying such varied phenomena as individual rationality in the philosophy of action and game theory, obligations in deontic logic (we should aim for the best of all possible worlds), or collective decisions in social choice theory. Also, in a more
The Interpretability Logic of all Reasonable Arithmetical Theories
 ERKENNTNIS
, 1999
"... This paper is a presentation of a status quaestionis, to wit of the problem of the interpretability logic of all reasonable arithmetical theories. We present both the arithmetical side and the modal side of the question. ..."
Abstract

Cited by 9 (5 self)
 Add to MetaCart
This paper is a presentation of a status quaestionis, to wit of the problem of the interpretability logic of all reasonable arithmetical theories. We present both the arithmetical side and the modal side of the question.
Yet More Modal Logics of Preference Change and Belief Revision
"... We contrast Bonanno’s ‘Belief Revision in a Temporal Framework ’ [15] with preference change and belief revision from the perspective of dynamic epistemic logic (DEL). For that, we extend the logic of communication and change of [11] with relational substitutions [8] for preference change, and show ..."
Abstract

Cited by 4 (2 self)
 Add to MetaCart
We contrast Bonanno’s ‘Belief Revision in a Temporal Framework ’ [15] with preference change and belief revision from the perspective of dynamic epistemic logic (DEL). For that, we extend the logic of communication and change of [11] with relational substitutions [8] for preference change, and show that this does not alter its properties. Next we move to a more constrained context where belief and knowledge can be defined from preferences [29; 14; 5; 7], prove completeness of a very expressive logic of belief revision, and define a mechanism for updating belief revision models using a combination of action priority update [7] and preference substitution [8]. 1 Reconstructing AGM Style Belief Revision Bonanno’s paper offers a rational reconstruction of Alchourrón Gärdenfors Makinson style belief revision (AGM belief revision) [1] (see also [22] and [23]), in a framework where modalities B for single agent belief and I for