the concept of forgetting has received significant interest in artificial intelligence recently. Informally, given a knowledge base, we may wish to forget about (or discard) some redundant parts (such as atoms, predic...
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ISBN:
(纸本)9783642287176
the concept of forgetting has received significant interest in artificial intelligence recently. Informally, given a knowledge base, we may wish to forget about (or discard) some redundant parts (such as atoms, predicates, concepts, etc) but still preserve the consequences for certain forms of reasoning. In nonmonotonicreasoning, so far forgetting has been studied only in the context of extension based approaches, mainly answer-set programming. In this paper forgetting is studied in the context of defeasible logic, which is a simple, efficient and sceptical nonmonotonicreasoning approach.
Propositional satisfiability (SAT) solvers provide a promising computational platform for logic programs under the stable model semantics. However. computing stable models of a logic program using a SAT solver presume...
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ISBN:
(纸本)9783642042379
Propositional satisfiability (SAT) solvers provide a promising computational platform for logic programs under the stable model semantics. However. computing stable models of a logic program using a SAT solver presumes translating the program into a set of clauses which is the input form accepted by most SAT solvers. this leads to fairly complex super-linear translations. there are, however, interesting extensions to plain clausal propositional representations Such as difference logic. A number of solvers have been developed for difference logic, in particular in the context of the satisfiability modulo theories (SMT) framework. and the goal of the paper is to study whether Such engines could be harnessed to the computation of stable models for logic programs in an effective way. To this end, we provide succinct translations front logic programs to theories of difference logic and evaluate the potential of SMT solvers in the computation of stable models using, these translations and a selection of benchmarks.
We present a purely model-theoretic semantics for disjunctive logic programs with negation, building on the infinite-valued approach recently introduced for normal logic programs [9]. In particular, we show that every...
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ISBN:
(纸本)9783540721994
We present a purely model-theoretic semantics for disjunctive logic programs with negation, building on the infinite-valued approach recently introduced for normal logic programs [9]. In particular, we show that every disjunctive logic program with negation has a non-empty set of minimal infinite-valued models. Moreover, we show that the infinite-valued semantics can be equivalently defined using Kripke models, allowing us to prove some properties of the new semantics more concisely. In particular, for programs without negation, the new approach collapses to the usual minimal model semantics, and when restricted to normal logic programs, it collapses to the well-founded semantics. Lastly, we show that every (propositional) program has a finite set of minimal infinite-valued models which can be identified by restricting attention to a finite subset of the truth values of the underlying logic.
the paper introduces Answer Set programming with External Predicates (ASP-EX), a framework aimed at enabling ASP to deal with external sources of computation. this feature is realized by the introduction of "para...
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ISBN:
(纸本)3540285385
the paper introduces Answer Set programming with External Predicates (ASP-EX), a framework aimed at enabling ASP to deal with external sources of computation. this feature is realized by the introduction of "parametric" external predicates, whose extension is not specified by means of a logic program but computed through external code. With respect to existing approaches it is explicitly addressed the issue of invention of new information coming from external predicates, in form of new, and possibly infinite, constant symbols. Several decidable restrictions of the language are identified as well as suitable algorithms for evaluating Answer Set Programs with external predicates. the framework paves the way to Answer Set programming in several directions such as pattern manipulation applications, as well as the possibility to exploit function symbols. ASP-EX has been successfully implemented in the DLV system, which is now enabled to make external program calls.
We propose a history-based approximation of the Possible Worlds Semantics (PWS) for reasoning about knowledge and action. A respective planning system is implemented by a transformation of the problem domain to an Ans...
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ISBN:
(纸本)9783642405648
We propose a history-based approximation of the Possible Worlds Semantics (PWS) for reasoning about knowledge and action. A respective planning system is implemented by a transformation of the problem domain to an Answer-Set Program. the novelty of our approach is elaboration tolerant support for postdiction under the condition that the plan existence problem is still solvable in NP, as compared to Sigma(P)(2) for non-approximated PWS of Son and Baral [20]. We demonstrate our planner with standard problems and present its integration in a cognitive robotics framework for high-level control in a smart home.
We present an extension epsilon L+perpendicular to T of the description logic epsilon L+perpendicular to for reasoning about prototypical properties and inheritance with exceptions. epsilon L+perpendicular to T is obt...
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ISBN:
(纸本)9783642042379
We present an extension epsilon L+perpendicular to T of the description logic epsilon L+perpendicular to for reasoning about prototypical properties and inheritance with exceptions. epsilon L+perpendicular to T is obtained by adding to epsilon L+perpendicular to a typicality operator T, which is intended to select the "typical" instances of a concept. In epsilon L+perpendicular to T knowledge bases may contain inclusions of the form "T(C) is subsumed by P", expressing that typical C-members have the property P. We show that the problem of entailment in epsilon L+perpendicular to T is in CO-NP.
the causal rejection-based update semantics assign meanings to a Dynamic logic Program (DLP), which is a sequence of logic programs each one updating the preceding ones. Although there are translations of DLPs under t...
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ISBN:
(纸本)9783319616605;9783319616599
the causal rejection-based update semantics assign meanings to a Dynamic logic Program (DLP), which is a sequence of logic programs each one updating the preceding ones. Although there are translations of DLPs under these update semantics to logic programs of Answer Set programming (ASP), they have not led to efficient and easy to use implementations. this is mainly because such translations aim offline solving in a sense that the resulting logic program is given to an answer set solver to compute models of the current DLP and for any future updates the whole process has to be repeated from scratch. We aim to remedy this situation by utilizing multi-shot ASP, composed of iterative answer set computations of a changing program without restarting from scratch at every step. To this end, we developed a system called moviola, utilizing the multi-shot answer set solver clingo. Using the system, a user can interactively write a DLP, update it, compute its models according to various semantics on the fly.
We report on preliminary research towards native algorithms for query answering over relational nonmonotonic Multi-Context Systems (MCS), i.e., algorithms that do not rely on computing equilibria. Inspired by techniqu...
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ISBN:
(纸本)9783642405648
We report on preliminary research towards native algorithms for query answering over relational nonmonotonic Multi-Context Systems (MCS), i.e., algorithms that do not rely on computing equilibria. Inspired by techniques for query answering in distributed answer set programming, we identify MCS settings where a generalized query answering algorithm is effective and efficient;confirmed by a preliminary evaluation on a real world application.
Our ultimate goal is to conceive an extension of Answer Set programming with language constructs from dynamic (and temporal) logic to provide an expressive computational framework for modeling dynamic applications. To...
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ISBN:
(纸本)9783030205287;9783030205270
Our ultimate goal is to conceive an extension of Answer Set programming with language constructs from dynamic (and temporal) logic to provide an expressive computational framework for modeling dynamic applications. To address this in a semantically well founded way, we generalize the definition of Dynamic Equilibrium logic to accommodate finite linear time and extend it with a converse operator in order to capture past temporal operators. this results in a general logical framework integrating existing dynamic and temporal logics of Here-and-there over both finite and infinite time. In the context of finite time, we then develop a translation of dynamic formulas into propositional ones that can in turn be translated into logic programs.
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