A general framework for revision of nonmonotonictheories is presented. this framework can be applied if the intended nonmonotonic semantics is not (weakly) cumulative. For weaker-semantics, it is shown that revision ...
详细信息
ISBN:
(纸本)3540632557
A general framework for revision of nonmonotonictheories is presented. this framework can be applied if the intended nonmonotonic semantics is not (weakly) cumulative. For weaker-semantics, it is shown that revision by contraction is not possible whenever the intended semantics satisfies Weak Cut and revision by expansion fails whenever Weak (Cautious) Monotony fails. Furthermore, it turns out that revision by expansion can be used to test whether the framework can be applied successfully and we analyse the case for logicprogramming.
We propose a novel formal framework (called 3D-NCDC-ASP) to represent and reason about cardinal directions between extended objects in 3-dimensional (3D) space, using Answer Set programming (ASP). 3D-NCDC-ASP extends ...
详细信息
We propose a novel formal framework (called 3D-NCDC-ASP) to represent and reason about cardinal directions between extended objects in 3-dimensional (3D) space, using Answer Set programming (ASP). 3D-NCDC-ASP extends Cardinal Directional Calculus (CDC) with a new type of default constraints, andNCDC-ASP to 3D. 3D-NCDC-ASP provides a flexible platform offering different types of reasoning: nonmonotonicreasoning with defaults, checking consistency of a set of constraints on 3D cardinal directions between objects, explaining inconsistencies, and inferring missing CDC relations. We prove the soundness of 3D-NCDC-ASP, and illustrate its usefulness with applications.
We study the fixed-parameter complexity of various problems in Al and nonmonotonicreasoning. We show that a number of relevant parameterized problems in these areas are fixed-parameter tractable. Among these problems...
详细信息
ISBN:
(纸本)3540667490
We study the fixed-parameter complexity of various problems in Al and nonmonotonicreasoning. We show that a number of relevant parameterized problems in these areas are fixed-parameter tractable. Among these problems are constraint satisfaction problems with bounded treewidth and fixed domain, restricted satisfiability problems, propositional logicprogramming under the stable model semantics where the parameter is the dimension of a feedback vertex set of the program's dependency graph, and circumscriptive inference from a positive k-CNF restricted to models of bounded size. We also show that circumscriptive inference from a general propositional theory, when the attention is restricted to models of bounded size, is fixed-parameter intractable and is actually complete for a novel fixed-parameter complexity class.
In answer-set programming (ASP), many notions of program equivalence have been introduced and formally analysed. A particular line of research in this direction aims at studying conditions under which certain syntacti...
详细信息
ISBN:
(纸本)9783642042379
In answer-set programming (ASP), many notions of program equivalence have been introduced and formally analysed. A particular line of research in this direction aims at studying conditions under which certain syntactic constructs can be eliminated from programs preserving some given equivalence relation. In this paper, we continue this endeavour introducing novel conditions under which disjunction and negation can be eliminated from answer-set programs under relativised strong equivalence with projection. this notion is a generalisation of the usual strong-equivalence relation, as introduced by Lifschitz. Pearce, and Valverde, by allowing parametrisable context and Output alphabets, which is an important feature in view of practical programming techniques like the use of local variables and modules. We provide model-theoretic conditions that hold for a disjunctive logic program P precisely when there is a program Q, equivalent to P under our considered notion, Such that Q is either positive, normal, or Horn, respectively. Moreover, we outline how such a Q, called a casting of P, can be obtained, and consider complexity issues.
Prioritized logic programs (PLPs) have a mechanism of representing priority knowledge in logic programs. the declarative semantics of a PLP is given as preferred answer sets which are used for representing nonmonotoni...
详细信息
ISBN:
(数字)9783540398134
ISBN:
(纸本)3540201017
Prioritized logic programs (PLPs) have a mechanism of representing priority knowledge in logic programs. the declarative semantics of a PLP is given as preferred answer sets which are used for representing nonmonotonicreasoning as well as preference abduction. From the computational viewpoint, however, its implementation issues have little been studied and no sound procedure is known for computing preferred answer sets of PLPs. In this paper, we present a sound and complete procedure to compute all preferred answer sets of a PLP in answer set programming. the procedure is based on a program transformation from a PLP to a logic program and is realized on top of any procedure for answer set programming. the proposed technique also extends PLPs to handle dynamic preference and we address its application to legal reasoning.
Argumentation has gained popularity in AI in recent years to support several activities and forms of reasoning. this talk will trace back the logicprogramming and non-monotonic reasoning origins of two well-known arg...
详细信息
ISBN:
(纸本)9783319616605;9783319616599
Argumentation has gained popularity in AI in recent years to support several activities and forms of reasoning. this talk will trace back the logicprogramming and non-monotonic reasoning origins of two well-known argumentation formalisms in AI (namely abstract argumentation and assumption-based argumentation). Finally, the talk will discuss recent developments in AI making use of computational argumentation, in particular to support collaborative decision making.
ID-logic uses ideas from the field of logicprogramming to extend second order logic with non-monotone inductive defintions. In this work, we reformulate the semantics of this logic in terms of approximation theory, a...
详细信息
ISBN:
(纸本)3540285385
ID-logic uses ideas from the field of logicprogramming to extend second order logic with non-monotone inductive defintions. In this work, we reformulate the semantics of this logic in terms of approximation theory, an algebraic theory which generalizes the semantics of several non-monotonic reasoning formalisms. this allows us to apply certain abstract modularity theorems, developed within the framework of approximation theory, to ID-logic. As such, we are able to offer elegant and simple proofs of generalizations of known theorems, m well as some new results.
Several learning systems based on Inverse Entailment (IE) have been proposed, some that compute single clause hypotheses, exemplified by Progol, and others that, produce multiple clauses in response to a single seed e...
详细信息
ISBN:
(纸本)9783642042379
Several learning systems based on Inverse Entailment (IE) have been proposed, some that compute single clause hypotheses, exemplified by Progol, and others that, produce multiple clauses in response to a single seed example. A common denominator of these systems, is a restricted hypothesis search space, within which each clause must individually explain some example E, or some member of an abductive explanation for E. this paper proposes a new IE approach, called Induction on Failure (IoF), that generalises existing Horn clause learning systems by allowing the computation of hypotheses within a larger search space, namely that of Connected theories. A proof procedure for IoF is proposed that generalises existing IE systems and also resolves Yamamoto's example. A prototype implementation is also described. Finally, a semantics is presented called Connected theory Generalisation, which is proved to extend Kernel Set Subsumption and to include hypotheses constructed within this new IoF approach.
We introduce a general approach to cryptographic protocol verification based oil answer set programming. In our approach, cryptographic protocols are represented as extended logic programs where the answer Sets corres...
详细信息
ISBN:
(纸本)9783642042379
We introduce a general approach to cryptographic protocol verification based oil answer set programming. In our approach, cryptographic protocols are represented as extended logic programs where the answer Sets correspond to traces of protocol runs. Using queries, we can find attacks on a protocol by finding the answer sets for the corresponding logic program. Our encoding is modular, with different modules representing the message passing environment, the protocol Structure and the intruder model. We can easily tailor each module to suit a specific application, while keeping the rest of the encoding constant. As such. our approach is more flexible and elaboration tolerant than related formalizations. the present system is intended as a first step towards the development of a compiler from protocol specifications to executable programs: such a compiler would make verification a completely automated process. this work is also part of a larger project in which we are exploring the advantages of explicit, declarative representations of protocol verification problems.
Answer Set programming (ASP) is a prominent knowledge representation language with roots in logicprogramming and non-monotonic reasoning. Biennial competitions are organized in order to furnish challenging benchmark ...
详细信息
ISBN:
(纸本)9783319616605;9783319616599
Answer Set programming (ASP) is a prominent knowledge representation language with roots in logicprogramming and non-monotonic reasoning. Biennial competitions are organized in order to furnish challenging benchmark collections and assess the advancement of the state of the art in ASP solving. In this paper, we report about the design of the Seventh ASP Competition, which is jointly organized by the University of Calabria (Italy), the University of Genova (Italy), and the University of Potsdam (Germany), in affiliation withthe 14thinternationalconference on logicprogramming and Non-Monotonic reasoning (LPNMR 2017). A novel feature of this competition edition is the re-introduction of a Model&Solve track, complementing the usual System track with problem domains where participants need to provide dedicated encodings and solving means.
暂无评论