We describe the new version of the PDDL-to-ASP translator plasp. First, it widens the range of accepted PDDL features. Second, it contains novel planning encodings, some inspired by SAT planning and others exploiting ...
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ISBN:
(纸本)9783319616605;9783319616599
We describe the new version of the PDDL-to-ASP translator plasp. First, it widens the range of accepted PDDL features. Second, it contains novel planning encodings, some inspired by SAT planning and others exploiting ASP features such as well-foundedness. All of them are designed for handling multi-valued fluents in order to capture both PDDL as well as SAS planning formats. third, enabled by multi-shot ASP solving, it offers advanced planning algorithms also borrowed from SAT planning. As a result, plasp provides us with an ASP-based framework for studying a variety of planning techniques in a uniform setting. Finally, we demonstrate in an empirical analysis that these techniques have a significant impact on the performance of ASP planning.
Answer-Set programming (ASP) is a declarative programming paradigm. In this paper we discuss two related restrictions and present a novel modeling technique to overcome them: (1) Meta-reasoning about the collection of...
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ISBN:
(纸本)9783319616605;9783319616599
Answer-Set programming (ASP) is a declarative programming paradigm. In this paper we discuss two related restrictions and present a novel modeling technique to overcome them: (1) Meta-reasoning about the collection of answer sets of a program is in general only possible by external postprocessing, but not within the program. this prohibits the direct continuation of reasoning based on the answer to the query over a (sub) program's answer sets. (2) the saturation programming technique exploits the minimality criterion for answer sets of a disjunctive ASP program to solve co-NP-hard problems, which typically involve checking if a property holds for all objects in a certain domain. However, the technique is advanced and not easily applicable by average ASP users;moreover, the use of default-negation within saturation encodings is limited. In this paper, we present an approach which allows for brave and cautious query answering over normal subprograms within a disjunctive program in order to address restriction (1). the query answer is represented by a dedicated atom within each answer set of the overall program, which paves the way also for a more intuitive alternative to saturation encodings and allows also using default-negation within such encodings, which addresses restriction (2).
In this paper, we study a method for computing temporal equilibrium models, a generalisation of stable models for logic programs with temporal operators, as in Linear Temporal logic (LTL). To this aim, we focus on a s...
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ISBN:
(纸本)9783642208942;9783642208959
In this paper, we study a method for computing temporal equilibrium models, a generalisation of stable models for logic programs with temporal operators, as in Linear Temporal logic (LTL). To this aim, we focus on a syntactic subclass of these temporal logic programs called splitable and whose main property is satisfying a kind of "future projected" dependence present in most dynamic scenarios in Answer Set programming (ASP). Informally speaking, this property can be expressed as "past does not depend on the future." We show that for this syntactic class, temporal equilibrium models can be captured by an LTL formula, that results from the combination of two well-known techniques in ASP: splitting and loop formulas. As a result, an LTL model checker can be used to obtain the temporal equilibrium models of the program.
A conflict clause represents a backtracking solver’s analysis of why a conflict occurred. this analysis can be used to further prune the search space and to direct the search heuristic. the use of such clauses has be...
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Domains, such as Ambient Intelligence and Social Networks, are characterized by some common features including distribution of the available knowledge, entities with different backgrounds, viewpoints and operational e...
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ISBN:
(纸本)9783642208942;9783642208959
Domains, such as Ambient Intelligence and Social Networks, are characterized by some common features including distribution of the available knowledge, entities with different backgrounds, viewpoints and operational environments, and imperfect knowledge. Multi-Context Systems (MCS) has been proposed as a natural representation model for such environments, while recent studies have proposed adding non-monotonic features to MCS to address the issues of incomplete, uncertain and ambiguous information. In previous works, we introduced a non-monotonic extension to MCS and an argument-based reasoning model that handle imperfect context information based on defeasible argumentation. Here we propose alternative variants that integrate features such as partial preferences, ambiguity propagating and team defeat, and study the relations between the different variants in terms of conclusions being drawn in each case.
We consider a housekeeping domain with multiple cleaning robots and represent it in the action language C+. With such a formalization of the domain, a plan can be computed using the causal reasoner CCALC for each robo...
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ISBN:
(纸本)9783642208942
We consider a housekeeping domain with multiple cleaning robots and represent it in the action language C+. With such a formalization of the domain, a plan can be computed using the causal reasoner CCALC for each robot to tidy some part of the house. However, to find a plan that characterizes a feasible trajectory that does not collide with obstacles, we need to consider geometric reasoning as well. For that, we embed motion planning in the domain description using external predicates. For safe execution of feasible plans, we introduce a planning and monitoring algorithm so that the robots can recover from plan execution failures due to heavy objects that cannot be lifted alone. the coordination of robots to help each other is considered for such a recovery. We illustrate the applicability of this algorithm with a simulation of a housekeeping domain.
there are many different notions of "rule" in the literature. A key feature and main intuition of any such notion is that rules can be "applied" to derive conclusions from certain premises. More fo...
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ISBN:
(纸本)9783642405648
there are many different notions of "rule" in the literature. A key feature and main intuition of any such notion is that rules can be "applied" to derive conclusions from certain premises. More formally, a rule is viewed as a function that, when invoked on a set of known facts, can produce new facts. In this paper, we show that this extreme simplification is still sufficient to obtain a number of useful results in concrete cases. We define abstract rules as a certain kind of functions, provide them with a semantics in terms of (abstract) stable models, and explain how concrete normal logicprogramming rules can be viewed as abstract rules in a variety of ways. We further analyse dependencies between abstract rules to recognise classes of logic programs for which stable models are guaranteed to be unique.
this volume contains the refereed proceedings of the 13thinternationalconference on logicprogramming and nonmonotonicreasoning, LPNMR 2015, held in September 2015 in Lexington, KY, USA. the 290long and 11 short pa...
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ISBN:
(数字)9783319232645
ISBN:
(纸本)9783319232638
this volume contains the refereed proceedings of the 13thinternationalconference on logicprogramming and nonmonotonicreasoning, LPNMR 2015, held in September 2015 in Lexington, KY, USA. the 290long and 11 short papers presented together with 3 invited talks, the paper reporting on the Answer Set programming competition, and four papers presented by LPNMR student attendees at the doctoral consortium were carefully reviewed and selected from 60 submissions. LPNMR is a forum for exchanging ideas on declarative logicprogramming, nonmonotonicreasoning, and knowledge representation. the aim of the LPNMR conferences is to facilitate interactions between researchers interested in the design and implementation of logic-based programming languages and database systems, and researchers who work in the areas of knowledge representation and nonmonotonicreasoning.
Global Abduction (GA) is a recently proposed logical formalism for agent oriented programming which allows an agent to collect information about the world and update this in a nonmonotonic: way when changes in the wor...
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ISBN:
(纸本)9783540696186
Global Abduction (GA) is a recently proposed logical formalism for agent oriented programming which allows an agent to collect information about the world and update this in a nonmonotonic: way when changes in the world are observed. A distinct feature of Global Abduction is that in case the agent needs to give up one plan, it may start a new one, or continue a suspended plan, while its beliefs learned about the world in the failed attempts persist. this paper describes an implementation of GA in the high-level language of Constraint Handling Rules (CHR). It appears to be a first attempt to a full implementation of GA, which also confirms CHR as a powerful meta-programming language for advanced reasoning. the construction gives rise a discussion of important issues of the semantics and pragmatics of Global Abduction, leading to proposals for a specific procedural semantics and architecture that seem well suited for real-time applications.
this paper proposes a new knowledge representation language, called QDLP, which extends DLP to deal with uncertain values. A certainty degree interval (a subinterval of [0, 1]) is assigned to each (quantitative) rule....
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ISBN:
(纸本)3540667490
this paper proposes a new knowledge representation language, called QDLP, which extends DLP to deal with uncertain values. A certainty degree interval (a subinterval of [0, 1]) is assigned to each (quantitative) rule. Triangular norms (T-norms) are employed to define calculi for propagating uncertainty information from the premises to the conclusion of a quantitative rule. Negation is considered and the concept of stable model is extended to QDLP. Different T-norms induce different semantics for one given quantitative program. In this sense, QDLP is parameterized and each choice of a T-norm induces a different QDLP language. Each T-norm is eligible for events with determinate relationships (e.g., independence, exclusiveness) between them. Since there are infinitely many T-norms, it turns out that there is a family of infinitely many QDLP languages. this family is carefully studied and the set of QDLP languages which generalize traditional DLP is precisely singled out. Finally the complexity of the main decisional problems arising in the context of QDLP (i.e., Model Checking, Stable Model Checking, Consistency, and Brave reasoning) is analyzed. It is shown that the complexity of the relevant fragments of QDLP coincides exactly withthe complexity of DLP. that is, reasoning with uncertain values is more general and not harder than reasoning with boolean values.
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