We briefly describe the answer set programming system DLV, focusing on some of its peculiar features and mentioning a number of successful applications.
We briefly describe the answer set programming system DLV, focusing on some of its peculiar features and mentioning a number of successful applications.
State-of-the-art ASP systems are 2-phased: first they ground the input program and then they solve the variable-free ground program. This may increase the size of the input program even exponentially, making ASP infea...
详细信息
State-of-the-art ASP systems are 2-phased: first they ground the input program and then they solve the variable-free ground program. This may increase the size of the input program even exponentially, making ASP infeasible for many practical applications. Lazy grounding, as in the recent Alpha ASP system, interleaves grounding and solving to avoid this so-called grounding bottleneck. Alpha demonstrates, for the first time in lazy grounding, efficient solving capabilities also for larger problems. The DynaCon research project addresses issues of dynamic reconfiguration in cyber-physical systems, a novel emerging application domain of ASP. Alpha is a promising start for such large-scale systems that need continuous reconfiguration to adapt to a changing environment.
Nieuwenhuis et al. (2006. Solving SAT and SAT modulo theories: From an abstract Davis-Putnam-Logemann-Loveland procedure to DPLL(T). Journal of the ACM 53(6), 937977 showed how to describe enhancements of the Davis-Pu...
详细信息
Nieuwenhuis et al. (2006. Solving SAT and SAT modulo theories: From an abstract Davis-Putnam-Logemann-Loveland procedure to DPLL(T). Journal of the ACM 53(6), 937977 showed how to describe enhancements of the Davis-Putnam-Logemann-Loveland algorithm using transition systems, instead of pseudocode. We design a similar framework for several algorithms that generate answersets for logic programs: SMODELS, SMODELScc, asp-sat with Learning (CMODELS), and a newly designed and implemented algorithm sup. This approach to describe answerset solvers makes it easier to prove their correctness, to compare them, and to design new systems.
Action languages are formal models of parts of natural language that are designed to describe effects of actions. Many of these languages can be viewed as high-level notations of answerset programs structured to repr...
详细信息
Action languages are formal models of parts of natural language that are designed to describe effects of actions. Many of these languages can be viewed as high-level notations of answerset programs structured to represent transition systems. However, the form of answerset programs considered in the earlier work is quite limited in comparison with the modern answer set programming (ASP) language, which allows several useful constructs for knowledge representation, such as choice rules, aggregates and abstract constraint atoms. We propose a new action language called BC+, which closes the gap between action languages and the modern ASP language. The main idea is to define the semantics of BC+ in terms of general stable model semantics for propositional formulas, under which many modern ASP language constructs can be identified with shorthands for propositional formulas. Language BC+ turns out to be sufficiently expressive to encompass the best features of other action languages, such as languages B, C, C+ and BC. Computational methods available in ASP solvers are readily applicable to compute BC+, which led to an implementation of the language by extending system CPLUS2ASP.
Both hybrid automata and action languages are formalisms for describing the evolution of dynamic systems. This paper establishes a formal relationship between them. We show how to succinctly represent hybrid automata ...
详细信息
Both hybrid automata and action languages are formalisms for describing the evolution of dynamic systems. This paper establishes a formal relationship between them. We show how to succinctly represent hybrid automata in an action language which in turn is defined as a high-level notation for answer set programming modulo theories-an extension of answerset programs to the firstorder level similar to the way satisfiability modulo theories (SMT) extends propositional satisfiability (SAT). We first show how to represent linear hybrid automata with convex invariants by an action language modulo theories. A further translation into SMT allows for computing them using SMT solvers that support arithmetic over reals. Next, we extend the representation to the general class of non-linear hybrid automata allowing even non-convex invariants. We represent them by an action language modulo ordinary differential equations, which can be compiled into satisfiability modulo ordinary differential equations. We present a prototype system CPLUS2ASPMT based on these translations, which allows for a succinct representation of hybrid transition systems that can be computed effectively by the state-of-the-art SMT solver dReal.
In this work, the Affective Logic (AFFLOG) Tutor is presented. An Affective Tutoring System that uses knowledge representation and reasoning tools such as answer set programming and the Event Calculus (EC) in order to...
详细信息
ISBN:
(纸本)9783030496630;9783030496623
In this work, the Affective Logic (AFFLOG) Tutor is presented. An Affective Tutoring System that uses knowledge representation and reasoning tools such as answer set programming and the Event Calculus (EC) in order to represent the main components of the tutor. AI Planning is used to select individual parts of a given course material (tutorials) in order to build a specific course tailored to the needs of each user according to the user's learning preferences. This course can dynamically change during the teaching session responding to the user's mental and emotional states, providing affective support by offering praise, consolation or encouragement depending on the current emotion of the user. The design and a functioning implementation of the system is presented. As a proof of concept, a course on how to play the settlers of Catan (c) board game was designed and implemented.
In complex reasoning tasks, as expressible by answer set programming (ASP), problems often permit for multiple solutions. In dynamic environments, where knowledge is continuously changing, the question arises how a gi...
详细信息
In complex reasoning tasks, as expressible by answer set programming (ASP), problems often permit for multiple solutions. In dynamic environments, where knowledge is continuously changing, the question arises how a given model can be incrementally adjusted relative to new and outdated information. This paper introduces Ticker, a prototypical engine for well-defined logical reasoning over streaming data. Ticker builds on a practical fragment of the recent rule-based language LARS, which extends ASP for streams by providing flexible expiration control and temporal modalities. We discuss Ticker's reasoning strategies: first, the repeated one-shot solving mode calls Clingo on an ASP encoding. We show how this translation can be incrementally updated when new data is streaming in or time passes by. Based on this, we build on Doyle's classic justification-based truth-maintenance system to update models of non-stratified programs. Finally, we empirically compare the obtained evaluation mechanisms.
This paper develops automated testing and debugging techniques for answerset solver development. We describe a flexible grammar-based black-box ASP fuzz testing tool which is able to reveal various defects such as un...
详细信息
This paper develops automated testing and debugging techniques for answerset solver development. We describe a flexible grammar-based black-box ASP fuzz testing tool which is able to reveal various defects such as unsound and incomplete behavior, i.e. invalid answersets and inability to find existing solutions, in state-of-the-art answerset solver implementations. Moreover, we develop delta debugging techniques for shrinking failure-inducing inputs on which solvers exhibit defective behavior. In particular, we develop a delta debugging algorithm in the context of answerset solving, and evaluate two different elimination strategies for the algorithm.
We present a new approach to enhancing answer set programming (ASP) with Constraint Processing techniques which allows for solving interesting Constraint Satisfaction Problems in ASP. We show how constraints on finite...
详细信息
We present a new approach to enhancing answer set programming (ASP) with Constraint Processing techniques which allows for solving interesting Constraint Satisfaction Problems in ASP. We show how constraints on finite domains can be decomposed into logic programs such that unit-propagation achieves arc, bound or range consistency. Experiments with our encodings demonstrate their computational impact.
The repeated execution of reasoning tasks is desirable in many applicative scenarios, such as stream reasoning and event processing. When using answer set programming in such contexts, one can avoid the iterative gene...
详细信息
The repeated execution of reasoning tasks is desirable in many applicative scenarios, such as stream reasoning and event processing. When using answer set programming in such contexts, one can avoid the iterative generation of ground programs thus achieving a significant payoff in terms of computing time. However, this may require some additional amount of memory and/or the manual addition of operational directives in the declarative knowledge base at hand. We introduce a new strategy for generating series of monotonically growing propositional programs. The proposedovergrounded programs with tailoring(OPTs) can be updated and reused in combination with consecutive inputs. With respect to earlier approaches, ourtailored simplificationtechnique reduces the size of instantiated programs. A maintained OPT slowly grows in size from an iteration to another while the update cost decreases, especially in later iterations. In this paper we formally introduce tailored embeddings, a family of equivalence-preserving ground programs which are at the theoretical basis of OPTs and we describe their properties. We then illustrate an OPT update algorithm and report about our implementation and its performance.
暂无评论