Results 1 
8 of
8
Comparing ASP, CP, ILP on two Challenging Applications: Wire Routing and Haplotype Inference
"... Abstract. We study three declarative programming paradigms, Answer Set Programming ..."
Abstract

Cited by 2 (1 self)
 Add to MetaCart
(Show Context)
Abstract. We study three declarative programming paradigms, Answer Set Programming
A Unifying Framework for Structural Properties of CSPs: Definitions, Complexity, Tractability
"... Literature on Constraint Satisfaction exhibits the definition of several “structural ” properties that can be possessed by CSPs, like (in)consistency, substitutability or interchangeability. Current tools for constraint solving typically detect such properties efficiently by means of incomplete yet ..."
Abstract

Cited by 2 (0 self)
 Add to MetaCart
(Show Context)
Literature on Constraint Satisfaction exhibits the definition of several “structural ” properties that can be possessed by CSPs, like (in)consistency, substitutability or interchangeability. Current tools for constraint solving typically detect such properties efficiently by means of incomplete yet effective algorithms, and use them to reduce the search space and boost search. In this paper, we provide a unifying framework encompassing most of the properties known so far, both in CSP and other fields ’ literature, and shed light on the semantical relationships among them. This gives a unified and comprehensive view of the topic, allows new, unknown, properties to emerge, and clarifies the computational complexity of the various detection problems. In particular, among the others, two new concepts, fixability and removability emerge, that come out to be the ideal characterisations of values that may be safely assigned or removed from a variable’s domain, while preserving problem satisfiability. These two notions subsume a large number of known properties, including inconsistency, substitutability and others. Because of the computational intractability of all the propertydetection problems, by following the CSP approach we then determine a number of relaxations which provide sufficient conditions for their tractability. In particular, we exploit forms of language restrictions and local reasoning. 1.
year 2005/2006, mainly focused on two topics of Constraint Programming (CP): Problem Reformulation and Decomposition. 1 Research Context: Constraint Programming and
"... ..."
(Show Context)
Main manuscript file Click here to download Manuscript: main.tex 1 2 3 4 5 6 7 8
, 2007
"... This paper 1 deals with four solvers for combinatorial problems: the commercial stateoftheart solver Ilog opl, and the research ASP systems dlv, smodels and cmodels. The first goal of this research is to evaluate the relative performance of such systems when used in a purely declarative way, usin ..."
Abstract
 Add to MetaCart
(Show Context)
This paper 1 deals with four solvers for combinatorial problems: the commercial stateoftheart solver Ilog opl, and the research ASP systems dlv, smodels and cmodels. The first goal of this research is to evaluate the relative performance of such systems when used in a purely declarative way, using a reproducible and extensible experimental methodology. In particular, we consider a thirdparty problem library, i.e., the CSPLib, and uniform rules for modelling and instance selection. The second goal is to analyze the marginal effects of popular reformulation techniques on the various solving technologies. In particular, we consider structural symmetry breaking, the adoption of global constraints, and the addition of auxiliary predicates. Finally, we evaluate, on a subset of the problems, the impact of numbers and arithmetic constraints on the different solving technologies. Results show that there is not a single solver winning on all problems, and that reformulation is almost always beneficial: symmetrybreaking may be a good choice, but its complexity has to be carefully chosen, by taking into account also the particular solver used. Global constraints often, but not always, help opl, and the addition of auxiliary predicates is usually worth, especially when dealing with ASP solvers. Moreover, interesting synergies among the various modelling techniques exist. 1
Constraint Logic Programming
"... Abstract. Constraint Logic Programming (CLP) is one of the most successful branches of Logic Programming; it attracts the interest of theoreticians and practitioners, and it is currently used in many commercial applications. Since the original proposal, it has developed enormously: many languages an ..."
Abstract
 Add to MetaCart
(Show Context)
Abstract. Constraint Logic Programming (CLP) is one of the most successful branches of Logic Programming; it attracts the interest of theoreticians and practitioners, and it is currently used in many commercial applications. Since the original proposal, it has developed enormously: many languages and systems are now available either as open source programs or as commercial systems. Also, CLP has been one of the technologies able to recruit researchers from other communities to the declarative programming cause. Current CLP engines include technologies and results developed in other communities, which themselves discovered logic as an invaluable tool to model and solve reallife problems. 1 The CLP Paradigm Constraint Logic Programming (CLP) [7] represents a successful attempt to merge the best features of logic programming (LP) and constraint solving. Constraint solving [127, 6, 56, 31] includes a variety of expressive modelling
Evaluating ASP and commercial solvers on the
"... This paper1 deals with four solvers for combinatorial problems: the commercial stateoftheart solver ILOG oplstudio, and the research ASP systems dlv, smodels and cmodels. The first goal of this research is to evaluate the relative performance of such systems when used in a purely declarative way, ..."
Abstract
 Add to MetaCart
(Show Context)
This paper1 deals with four solvers for combinatorial problems: the commercial stateoftheart solver ILOG oplstudio, and the research ASP systems dlv, smodels and cmodels. The first goal of this research is to evaluate the relative performance of such systems when used in a purely declarative way, using a reproducible and extensible experimental methodology. In particular, we consider a thirdparty problem library, i.e., the CSPLib, and uniform rules for modelling and instance selection. The second goal is to analyze the marginal effects of popular reformulation techniques on the various solving technologies. In particular, we consider structural symmetry breaking, the adoption of global constraints, and the addition of auxiliary predicates. Finally, we evaluate, on a subset of the problems, the impact of numbers and arithmetic constraints on the different solving technologies. Results show that there is not a single solver winning on all problems, and that reformulation is almost always beneficial: symmetrybreaking may be a good choice, but its complexity has to be carefully chosen, by taking into account also the particular solver used. Global constraints often, but not always, help opl, and the addition of auxiliary predicates is usually worth, especially when dealing with ASP solvers. Moreover, interesting synergies among the various modelling techniques exist. 1