Gelfond's epistemic logic programs are not only an extension of disjunctive extended logic programs for handling difficulties in reasoning with incomplete information, but also an effective formalism to represent ...
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In this paper we present an effective prover for mbC, a minimal inconsistency logic. the mbC logic is a paraconsistent logic of the family of logics of formal inconsistency. Paraconsistent logics have several philosop...
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ISBN:
(纸本)0387346546
In this paper we present an effective prover for mbC, a minimal inconsistency logic. the mbC logic is a paraconsistent logic of the family of logics of formal inconsistency. Paraconsistent logics have several philosophical motivations as well as many applications in artificialintelligence such as in belief revision, inconsistent knowledge reasoning, and logicprogramming. We have implemented the KEMS prover for mbC, a theorem prover based on the KE tableau method for mbC. We show here that the proof system on which this prover is based is sound, complete and analytic. To evaluate the KEMS prover for mbC, we devised four families of mbC-valid formulas and we present here the first benchmark results using these families.
Recently, in (Loyer & Straccia 2005) the Any-World Assumption (AWA) has been introduced for normal logic programs as a generalization of the well-known notions of Closed World Assumption (CWA) and the Open World A...
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We investigate in this work a generalization of the known CNF representation which allows an efficient Boolean encoding for n-ary CSPs. We show that the space complexity of the Boolean encoding is identical to the one...
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ISBN:
(纸本)3540409300
We investigate in this work a generalization of the known CNF representation which allows an efficient Boolean encoding for n-ary CSPs. We show that the space complexity of the Boolean encoding is identical to the one of the classical CSP representation and introduce a new inference rule whose application until saturation achieves arc-consistency in a linear time complexity for n-ary CSPs expressed in the Boolean encoding. Two enumerative methods for the Boolean encoding are studied: the first one (equivalent to MAC in CSPs) maintains full arc-consistency on each node of the search tree while the second (equivalent to FC in CSPs) performs partial arc-consistency on each node. Both methods are experimented and compared on some instances of the Ramsey problem and randomly generated 3-ary CSPs and promising results are obtained.
Recognizing and extracting meaningful information from unstructured documents, taking into account their semantics, is an important problem in the field of information and knowledge management. In this paper we descri...
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ISBN:
(纸本)9728865422
Recognizing and extracting meaningful information from unstructured documents, taking into account their semantics, is an important problem in the field of information and knowledge management. In this paper we describe a novel logic-based approach to semantic information extraction, from both HTML pages and flat text documents, implemented in the HlLEX system. the approach is founded on a new two-dimensional representation of documents, and heavily exploits DLP+ - an extension of disjunctive logicprogramming for ontology representation and reasoning, which has been recently implemented on top of the DLV system. Ontologies, representing the semantics of information to be extracted, are encoded in DLP+, while the extraction patterns are expressed using regular expressions and an ad hoc two-dimensional grammar. the execution of DLP+ reasoning modules, encoding the HlL epsilon X grammar expressions, yields the actual extraction of information from the input document. Unlike previous systems, which are merely syntactic, HlL epsilon X combines both semantic and syntactic knowledge for a powerful information extraction.
Revising and updating beliefs and knowledge bases is an important topic in knowledge representation and reasoning. Various proposals have been made for updating logic programs, in particular with respect to Answer Set...
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the contribution of this paper consists in some techniques to bound the proof search space in propositional intuitionistic logic. these techniques are justified by Kripke semantics and they are the backbone of a table...
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the contribution of this paper consists in some techniques to bound the proof search space in propositional intuitionistic logic. these techniques are justified by Kripke semantics and they are the backbone of a tableau based theorem prover (PITP) implemented in C++ language. PITP and some known theorem provers are compared by the formulas of ILTP v1.1.1 benchmark library. It turns out that PITP is, at the moment, the propositional prover that solves most formulas of the library.
In this paper, we propose a formal framework for specifying rule replacements in nonmonotonic logic programs within the answer-set programming paradigm. Of particular interest are replacement schemas retaining specifi...
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High-performance SAT solvers based on systematic search generally use either conflict driven clause learning (CDCL) or lookahead techniques to gain efficiency. Both styles of reasoning can gain from a preprocessing ph...
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High-performance SAT solvers based on systematic search generally use either conflict driven clause learning (CDCL) or lookahead techniques to gain efficiency. Both styles of reasoning can gain from a preprocessing phase in which some form of deduction is used to simplify the problem. In this paper we undertake an empirical examination of the effects of several recently proposed preprocessors on both CDCL and lookahead-based SAT solvers. One finding is that the use of multiple preprocessors one after the other can be much more effective than using any one of them alone, but that the order in which they are applied is significant. We intend our results to be particularly useful to those implementing new preprocessors and solvers.
In systems where agents are required to interact with a partially known and dynamic world, sensors can be used to obtain further knowledge about the environment. However, sensors may be unreliable, that is, they may d...
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ISBN:
(纸本)0387346546
In systems where agents are required to interact with a partially known and dynamic world, sensors can be used to obtain further knowledge about the environment. However, sensors may be unreliable, that is, they may deliver wrong information (due, e.g., to hardware or software malfunctioning) and, consequently, they may cause agents to take wrong decisions, which is a scenario that should be avoided. the paper considers the problem of reasoning in noisy environments in a setting where no (either certain or probabilistic) data is available in advance about the reliability of sensors. therefore, assuming that each agent is equipped with a background theory (in our setting, an extended logic program) encoding its general knowledge about the world, we define a concept of detecting an anomaly perceived in sensor data and the related concept of agent recovering to a coherent status of information. In this context, the complexities of various anomaly detection and anomaly recovery problems are studied.
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