Extensional higher-order logicprogramming has been introduced as a generalization of classical logicprogramming. An important characteristic of this paradigm is that it preserves all the well-known properties of tra...
Extensional higher-order logicprogramming has been introduced as a generalization of classical logicprogramming. An important characteristic of this paradigm is that it preserves all the well-known properties of traditional logicprogramming. In this paper we consider the semantics of negation in the context of the new paradigm. Using some recent results from non-monotonic fixed-point theory, we demonstrate that every higher-order logic program with negation has a unique minimum infinite-valued model. In this way we obtain the first purely model-theoretic semantics for negation in extensional higher-order logicprogramming. Using our approach, we resolve an old paradox that was introduced by W. W. Wadge in order to demonstrate the semantic difficulties of higher-order logicprogramming.
Uncertainty in logicprogramming has been widely investigated in the last decades, leading to multiple extensions of the classical logicprogramming paradigm. However, few of these are designed as extensions of the we...
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Uncertainty in logicprogramming has been widely investigated in the last decades, leading to multiple extensions of the classical logicprogramming paradigm. However, few of these are designed as extensions of the well-established and powerful Constraint logicprogramming (CLP) scheme for CLP. In a previous work we have proposed the proximity-based qualified constraint logicprogramming (SQCLP) scheme as a quite expressive extension of CLP with support for qualification values and proximity relations as generalizations of uncertainty values and similarity relations, respectively. In this paper we provide a transformation technique for transforming SQCLP programs and goals into semantically equivalent CLP programs and goals, and a practical Prolog-based implementation of some particularly useful instances of the SQCLP scheme. We also illustrate, by showing some simple - and working - examples, how the prototype can be effectively used as a tool for solving problems where qualification values and proximity relations play a key role. Intended use of SQCLP includes flexible information retrieval applications.
We describe a framework to support the implementation of web-based systems intended to manipulate data stored in relational databases. Since the conceptual model of a relational database is often specified as an entit...
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We describe a framework to support the implementation of web-based systems intended to manipulate data stored in relational databases. Since the conceptual model of a relational database is often specified as an entity-relationship (ER) model, we propose to use the ER model to generate a complete implementation in the declarative programming language Curry. This implementation contains operations to create and manipulate entities of the data model, supports authentication, authorization, session handling, and the composition of individual operations to user processes. Furthermore, the implementation ensures the consistency of the database w.r.t. the data dependencies specified in the ER model, i.e., updates initiated by the user cannot lead to an inconsistent state of the database. In order to generate a high-level declarative implementation that can be easily adapted to individual customer requirements, the framework exploits previous works on declarative database programming and web user interface construction in Curry.
Describing complex objects by elementary ones is a common strategy in mathematics and science in general. In their seminal 1965 paper, Kenneth Krohn and John Rhodes showed that every finite deterministic automaton can...
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Describing complex objects by elementary ones is a common strategy in mathematics and science in general. In their seminal 1965 paper, Kenneth Krohn and John Rhodes showed that every finite deterministic automaton can be represented (or "emulated") by a cascade product of very simple automata. This led to an elegant algebraic theory of automata based on finite semigroups (Krohn-Rhodes theory). Surprisingly, by relating logic programs and automata, we can show in this paper that the Krohn-Rhodes theory is applicable in Answer Set programming (ASP). More precisely, we recast the concept of a cascade product to ASP, and prove that every program can be represented by a product of very simple programs, the reset and standard programs. Roughly, this implies that the reset and standard programs are the basic building blocks of ASP with respect to the cascade product. In a broader sense, this paper is a first step towards an algebraic theory of products and networks of nonmonotonic reasoning systems based on Krohn-Rhodes theory, aiming at important open issues in ASP and AI in general.
The paper presents a knowledge representation language Alog which extends ASP with aggregates. The goal is to have a language based on simple syntax and clear intuitive and mathematical semantics. We give some propert...
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The paper presents a knowledge representation language Alog which extends ASP with aggregates. The goal is to have a language based on simple syntax and clear intuitive and mathematical semantics. We give some properties of Alog, an algorithm for computing its answer sets, and comparison with other approaches.
The education and training for outstanding engineers is a comprehensive strategy. It relates to many aspects, such as curriculum development and teaching material selection, the investment of teaching equipments and e...
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The education and training for outstanding engineers is a comprehensive strategy. It relates to many aspects, such as curriculum development and teaching material selection, the investment of teaching equipments and experimental facilities, theory and practice teaching, performance evaluation mechanism, on campus study and off campus exercise, learning before graduation and application after graduation, and so on. It needs collaborative optimization and improvement together of these aspects. Programmable logic controller(PLC) has become a required course in engineering colleges, because of its wide application prospect. In this paper, we analyze the factors that influence the teaching and training of outstanding engineers taking the course of PLC as an example, and we illustrate the technique and methods that mastering PLC programming taking a large number of sequence control in power plant as examples.
We have designed a new logicprogramming language called LM (Linear Meld) for programming graph- based algorithms in a declarative fashion. Our language is based on linear logic, an expressive logical system where log...
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We have designed a new logicprogramming language called LM (Linear Meld) for programming graph- based algorithms in a declarative fashion. Our language is based on linear logic, an expressive logical system where logical facts can be consumed. Because LM integrates both classical and linear logic, LM tends to be more expressive than other logicprogramming languages. LM programs are naturally concurrent because facts are partitioned by nodes of a graph data structure. Computation is performed at the node level while communication happens between connected nodes. In this paper, we present the syntax and operational semantics of our language and illustrate its use through a number of examples.
Answer Set programming (ASP) is a well-established paradigm of declarative programming in close relationship with other declarative formalisms such as SAT Modulo Theories, Constraint Handling Rules, FO(.), PDDL and ma...
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Answer Set programming (ASP) is a well-established paradigm of declarative programming in close relationship with other declarative formalisms such as SAT Modulo Theories, Constraint Handling Rules, FO(.), PDDL and many others. Since its first informal editions, ASP systems have been compared in the now well-established ASP Competition. The Third (Open) ASP Competition, as the sequel to the ASP Competitions Series held at the University of Potsdam in Germany (2006-2007) and at the University of Leuven in Belgium in 2009, took place at the University of Calabria (Italy) in the first half of 2011. Participants competed on a pre-selected collection of benchmark problems, taken from a variety of domains as well as real world applications. The Competition ran on two tracks: the Model and Solve (M&S) Track, based on an open problem encoding, and open language, and open to any kind of system based on a declarative specification paradigm;and the System Track, run on the basis of fixed, public problem encodings, written in a standard ASP language. This paper discusses the format of the competition and the rationale behind it, then reports the results for both tracks. Comparison with the second ASP competition and state-of-the-art solutions for some of the benchmark domains is eventually discussed.
A key difficulty in verifying shared-memory concurrent programs is reasoning compositionally about each thread in isolation. Existing verification techniques for fine-grained concurrency typically require reasoning ab...
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Extensional higher-order logicprogramming has been introduced as a generalization of classical logicprogramming. An important characteristic of this paradigm is that it preserves all the well-known properties of tra...
详细信息
Extensional higher-order logicprogramming has been introduced as a generalization of classical logicprogramming. An important characteristic of this paradigm is that it preserves all the well-known properties of traditional logicprogramming. In this paper we consider the semantics of negation in the context of the new paradigm. Using some recent results from non-monotonic fixed-point theory, we demonstrate that every higher-order logic program with negation has a unique minimum infinite-valued model. In this way we obtain the first purely model-theoretic semantics for negation in extensional higher-order logicprogramming. Using our approach, we resolve an old paradox that was introduced by W. W. Wadge in order to demonstrate the semantic difficulties of higher-order logicprogramming.
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