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Answer Set Programming and Plan Generation
- ARTIFICIAL INTELLIGENCE
, 2002
"... The idea of answer set programming is to represent a given computational problem by a logic program whose answer sets correspond to solutions, and then use an answer set solver, such as smodels or dlv, to find an answer set for this program. Applications of this method to planning are related to the ..."
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Cited by 174 (6 self)
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The idea of answer set programming is to represent a given computational problem by a logic program whose answer sets correspond to solutions, and then use an answer set solver, such as smodels or dlv, to find an answer set for this program. Applications of this method to planning are related to the line of research on the frame problem that started with the invention of formal nonmonotonic reasoning in 1980.
Reasoning About Action I: A Possible Worlds Approach
- Artificial Intelligence
, 1987
"... Reasoning about change is an important aspect of commonsense reasoning and planning. In this paper we describe an approach to reasoning about change for rich domains where it is not possible to anticipate all situations that might occur. The approach provides a solution to the frame problem, and to ..."
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Cited by 161 (7 self)
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Reasoning about change is an important aspect of commonsense reasoning and planning. In this paper we describe an approach to reasoning about change for rich domains where it is not possible to anticipate all situations that might occur. The approach provides a solution to the frame problem, and to the related problem that it is not always reasonable to explicitly specify all of the consequences of actions. The approach involves keeping a single model of the world that is updated when actions are performed. The update procedure involves constructing the nearest world to the current one in which the consequences of the actions under consideration hold. The way we find the nearest world is to construct proofs of the negation of the explicit consequences of the expected action, and to remove a premise in each proof from the current world. Computationally, this construction procedure appears to be tractable for worlds like our own where few things tend to change with each action, or where ...
FORMAL THEORIES OF ACTION
, 1987
"... We apply circumscription to formalizing reasoning about the effects of actions in the framework of the situation calculus. The axiomatic description of causal connections between actions and changes allows us to solve the qualification problem and the frame problem using only simple forms of circums ..."
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Cited by 125 (2 self)
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We apply circumscription to formalizing reasoning about the effects of actions in the framework of the situation calculus. The axiomatic description of causal connections between actions and changes allows us to solve the qualification problem and the frame problem using only simple forms of circumscription. The method is applied to the Hanks—McDermott shooting problem and to a blocks world in which blocks can be moved and painted.
A Circumscriptive Calculus of Events
- Artificial Intelligence
, 1995
"... A calculus of events is presented in which domain constraints, concurrent events, and events with non-deterministic effects can be represented. The paper offers a non-monotonic solution to the frame problem for this formalism that combines two of the techniques developed for the situation calculus, ..."
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Cited by 81 (12 self)
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A calculus of events is presented in which domain constraints, concurrent events, and events with non-deterministic effects can be represented. The paper offers a non-monotonic solution to the frame problem for this formalism that combines two of the techniques developed for the situation calculus, namely causal and state-based minimisation. A theorem is presented which guarantees that temporal projection will not interfere with minimisation in this solution, even in domains with ramifications, concurrency, and non-determinism. Finally, the paper shows how the formalism can be extended to cope with continuous change, whilst preserving the conditions for the theorem to apply. 1 Introduction The frame problem was first described by McCarthy and Hayes in the Sixties [23], and has occupied the thoughts of AI researchers ever since. In a nutshell, the problem is this: if we deploy classical logic in a straightforward way to describe the effects of actions, we have to represent explicitl...
Impediments to Universal Preference-Based Default Theories
- Artificial Intelligence
, 1989
"... Research on nonmonotonic and default reasoning has identified several important criteria for preferring alternative default inferences. The theories of reasoning based on each of these criteria may uniformly be viewed as theories of rational inference, in which the reasoner selects maximally preferr ..."
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Cited by 72 (14 self)
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Research on nonmonotonic and default reasoning has identified several important criteria for preferring alternative default inferences. The theories of reasoning based on each of these criteria may uniformly be viewed as theories of rational inference, in which the reasoner selects maximally preferred states of belief. Though researchers have noted some cases of apparent conflict between the preferences supported by different theories, it has been hoped that these special theories of reasoning may be combined into a universal logic of nonmonotonic reasoning. We show that the different categories of preferences conflict more than has been realized, and adapt formal results from social choice theory to prove that every universal theory of default reasoning will violate at least one reasonable principle of rational reasoning. Our results can be interpreted as demonstrating that, within the preferential framework, we cannot expect much improvement on the rigid lexicographic priority mechanisms that have been proposed for conflict resolution.
Current Approaches to Handling Imperfect Information in Data and Knowledge Bases
, 1996
"... This paper surveys methods for representing and reasoning with imperfect information. It opens with an attempt to classify the different types of imperfection that may pervade data, and a discussion of the sources of such imperfections. The classification is then used as a framework for considering ..."
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Cited by 70 (1 self)
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This paper surveys methods for representing and reasoning with imperfect information. It opens with an attempt to classify the different types of imperfection that may pervade data, and a discussion of the sources of such imperfections. The classification is then used as a framework for considering work that explicitly concerns the representation of imperfect information, and related work on how imperfect information may be used as a basis for reasoning. The work that is surveyed is drawn from both the field of databases and the field of artificial intelligence. Both of these areas have long been concerned with the problems caused by imperfect information, and this paper stresses the relationships between the approaches developed in each.
Multivalued Logics: A Uniform Approach to Inference in Artificial Intelligence
- Computational Intelligence
, 1988
"... This paper describes a uniform formalization of much of the current work in AI on inference systems. We show that many of these systems, including first-order theorem provers, assumption-based truth maintenance systems (atms's) and unimplemented formal systems such as default logic or circumscr ..."
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Cited by 66 (0 self)
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This paper describes a uniform formalization of much of the current work in AI on inference systems. We show that many of these systems, including first-order theorem provers, assumption-based truth maintenance systems (atms's) and unimplemented formal systems such as default logic or circumscription can be subsumed under a single general framework. We begin by defining this framework, which is based on a mathematical structure known as a bilattice. We present a formal definition of inference using this structure, and show that this definition generalizes work involving atms's and some simple nonmonotonic logics. Following the theoretical description, we describe a constructive approach to inference in this setting; the resulting generalization of both conventional inference and atms's is achieved without incurring any substantial computational overhead. We show that our approach can also be used to implement a default reasoner, and discuss a combination of default and atms methods th...
Disjunctive Deductive Databases
, 1994
"... Background material is presented on deductive and normal deductive databases. A historical review is presented of work in disjunctive deductive databases, starting from 1982. The semantics of alternative classes of disjunctive databases is reviewed with their model and fixpoint characterizations. Al ..."
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Cited by 59 (7 self)
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Background material is presented on deductive and normal deductive databases. A historical review is presented of work in disjunctive deductive databases, starting from 1982. The semantics of alternative classes of disjunctive databases is reviewed with their model and fixpoint characterizations. Algorithms are developed to compute answers to queries in the alternative theories using the concept of a model tree. Open problems in this area are discussed.
Circumscriptive theories: a logic-based framework for knowledge representation
- Journal of Philosophical Logic
, 1988
"... Abstract The use of circumscription for formalizing commonsense knowledge and reasoning requires that a circumscription policy be selected for each particular application: we should specify which predicates are circumscribed, which predicates and functions are allowed to vary, what priorities betwe ..."
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Cited by 36 (1 self)
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Abstract The use of circumscription for formalizing commonsense knowledge and reasoning requires that a circumscription policy be selected for each particular application: we should specify which predicates are circumscribed, which predicates and functions are allowed to vary, what priorities between the circumscribed predicates are established, etc. The circumscription policy is usually described either informally or using suitable metamathematical notation. In this paper we propose a simple and general formalism which permits describing circumscription policies by axioms, included in the knowledge base along with the axioms describing the objects of reasoning. This method allows us to formalize some important forms of metalevel reasoning in the circumscriptive theory itself.
Simple causal minimizations for temporal persistence and projection
- In Proceedings of the 6th National Conference of Artificial Intelligence
, 1987
"... Formalizing temporal persistence and solving the temporal projection problem within traditional non-monotonic logics is shown possible through two different approaches, neither of which respecial minimization techniques. $$$z~ ~ potential causes is shown to yield a type of temporal persistence that ..."
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Cited by 36 (0 self)
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Formalizing temporal persistence and solving the temporal projection problem within traditional non-monotonic logics is shown possible through two different approaches, neither of which respecial minimization techniques. $$$z~ ~ potential causes is shown to yield a type of temporal persistence that is useful for the temporal projection problem, although it differs significantly from the ordinary conception of temporal persistence. A conception of determined causes is then developed whose minimization does yield the results preferred by ordinary temporal persistence. Finally, previous approaches to formalizing temporal persistence using chronological minimizations are shown inadequate for certain classes of scenarios, which causal minimizations formalize correctly. 1.
