Often graphs are used to investigate properties of logic programs. In general, different graphs represent different kinds of information of the corresponding programs. Sometimes this information is not sufficient for ...
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Often graphs are used to investigate properties of logic programs. In general, different graphs represent different kinds of information of the corresponding programs. Sometimes this information is not sufficient for solving a certain problem. In this paper we define graphs which are suitable for computing answer sets of different classes of logic programs. Intuitively, a graph associated to a logic program is suitable for answer set semantics if its structure is sufficient to compute the answer sets of the corresponding program. That is, algorithms that use suitable graphs do not have to consider the original logic program any longer. We investigate different classes of graphs which are suitable for answer set computation of normal nested logic programs, normal logic programs and normal programs with at most on positive body atom.
We present a progress report on ongoing work to investigate topologies on spaces of interpretations in which one obtains the continuity of the operators associated with the well-founded, and alternating fixed-point se...
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Our Faculty embarked a few years ago on an ambitious project to redesign itself around an integrated information system, aimed at supporting all information handling activities and deployed through dynamic Web interfa...
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ISBN:
(纸本)3540003894
Our Faculty embarked a few years ago on an ambitious project to redesign itself around an integrated information system, aimed at supporting all information handling activities and deployed through dynamic Web interfaces automatically customized for individual users. The project includes both the design of the services and the development of appropriate software technology to implement them. It led already to a running system, supporting many official academic procedures, which is under constant evolution. The system architecture is fully based on Prolog, connected to an external database engine. This paper summarizes and discusses the characteristics that make Prolog a vehicle of choice for the implementation, along with a sketch of main aspects of the system architecture and the specific declarative techniques that were developed for them. The recurring methodological gain is the ease of building abstraction layers supported by specific term sub-languages, due to the combination of flexible operator syntax with the power of the underlying machinery to define new constructs. The basic programming layer evolved from standard Prolog to a novel structured version of it, with compositional semantics (no cuts) and direct support for structural abstraction and application, combining in practice the logic programming style with the higher-order power and some of the programming flavour of functional languages. The system's main architectural glue is the conceptual scheme, for which a definition language was developed whose expressions are compiled (by Prolog) to induce the database tables and (the instantiation of) a query/update language with a syntax based on compositionality principles of natural language, whose expressions are both more natural and much more compact than the equivalent in SQL.
This paper presents a set of rules for reasoning about the truth values of states in knowledge systems using an interval-based representation of time. Two major sources of complexity, ambiguity in temporal networks an...
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ISBN:
(纸本)1932415122
This paper presents a set of rules for reasoning about the truth values of states in knowledge systems using an interval-based representation of time. Two major sources of complexity, ambiguity in temporal networks and the possibility of the persistence of states, are analyzed. Finally, both an exact though inefficient solution method and a more efficient approximate solution method are presented.
In this paper, we present a new language construct, called Action Rules (AR), and describe its application to the implementation of various constraint propagators and interactive graphical user interfaces. An action r...
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ISBN:
(纸本)354000680X
In this paper, we present a new language construct, called Action Rules (AR), and describe its application to the implementation of various constraint propagators and interactive graphical user interfaces. An action rule specifies a pattern for agents, an event pattern for events that can activate the agents, and an action that the agents carry out when activated. AR combines the goal-oriented execution model of logic programming with the event-driven execution model. This hybrid execution model facilitates programming interactions in applications such as constraint propagators and interactive user interfaces. A propagator for a constraint is an agent that maintains the consistency of the constraint and is activated by updates to the domain variables in the constraint. As graphics programming is concerned, an agent is an event handler that handles stimuli from the users. AR has been incorporated into B-Prolog (***). It has been successfully employed in the implementation of several efficient constraint solvers [24],[26] and in the CGLIB, a high-level constraint-based graphics library [25].
Language for Structured Design (LSD) is a high level, visual, logic programming language for design of structured objects. LSD combines the design and programming activities in a homogeneous programming/design environ...
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ISBN:
(纸本)1581137052
Language for Structured Design (LSD) is a high level, visual, logic programming language for design of structured objects. LSD combines the design and programming activities in a homogeneous programming/design environment by extending Lograph, a visual logic programming language, with the notion of solids and operations on them. At the back-end, however, a solid modeling kernel for maintaining low level description of solids and operations is required. In this paper, we report on our progress towards employing PLaSM, a functional programming language for solid modeling, as the solid modeling kernel of LSD. This is achieved through the use of a translator engine which transforms the high level object description produced by LSD programs to PLaSM programs.
In this paper we show how to transfer some developments done in the field of functional logic programming (FLP) to a pure functional setting (FP). More exactly, we propose a complete fold/unfold based transformation s...
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作者：
Mercer, R.E.Risch, V.Cognitive Engineering Laboratory
Department of Computer Science University of Western Ontario London ON N6A 5B7 Canada InCA Team
LSIS - UMR CNRS 6168 Domaine Universitaire de Saint-Jérôme avenue Escadrille Normandie Niemen 13397 Marseille cédex 20 France
In this paper we define the notion of a compatibility relation so as to have a common framework for three nonmonotonic reasoning systems: normal logic programming, extended logic programming, and a restricted form of ...
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In this paper we define the notion of a compatibility relation so as to have a common framework for three nonmonotonic reasoning systems: normal logic programming, extended logic programming, and a restricted form of default logic. We show some properties of the maximal cliques of the pair-wise compatibility graph givn by the relation between the rules of the various reasoning systems. Properties that these maximal cliques possess are presented. A procedure to compute stable models (resp. answer sets, extensions) by enumerating maximal cliques with intelligent pruning is sketched.
Concurrent constraint programming has been thought as providing coordination of concurrent processes on the basis of the availability and sharing of information. It classically incorporates a form of asynchronous comm...
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In this paper, we present an abstract framework for learning a finite domain constraint solver modeled by a set of operators enforcing a consistency. The behavior of the consistency to be learned is taken as the set o...
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In this paper, we present an abstract framework for learning a finite domain constraint solver modeled by a set of operators enforcing a consistency. The behavior of the consistency to be learned is taken as the set of examples on which the learning process is applied. The best possible expression of this operator in a given language is then searched. We instantiate this framework to the learning of bound-consistency in the indexical language of Gnu-Prolog.
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