DATALOG with Constraints - An Answer-set Programming System

Deborah East, Mirosław Truszczyński

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

9 Scopus citations


Answer-set programming (ASP) has emerged recently as a viable programming paradigm well attuned to search problems in AI, constraint satisfaction and combinatorics. Propositional logic is, arguably, the simplest ASP system with an intuitive semantics supporting direct modeling of problem constraints. However, for some applications, especially those requiring that transitive closure be computed, it requires additional variables and results in large theories. Consequently, it may not be a practical computational tool for such problems. On the other hand, ASP systems based on nonmonotonic logics, such as stable logic programming, can handle transitive closure computation efficiently and, in general, yield very concise theories as problem representations. Their semantics is, however, more complex. Searching for the middle ground, in this paper we introduce a new nonmonotonic logic, DATALOG with constraints or DC. Informally, DC theories consist of propositional clauses (constraints) and of Horn rules. The semantics is a simple and natural extension of the semantics of the propositional logic. However, thanks to the presence of Horn rules in the system, modeling of transitive closure becomes straightforward. We describe the syntax and semantics of DC, and study its properties. We discuss an implementation of DC and present results of experimental study of the effectiveness of DC, comparing it with the csat satisfiability checker and smodels implementation of stable logic programming. Our results show that DC is competitive with the other two approaches, in case of many search problems, often yielding much more efficient solutions.

Original languageEnglish
Title of host publicationProceedings of the 17th National Conference on Artificial Intelligence and 12fth Conference on Innovative Applications ofArtificial Intelligence, AAAI 2000
Number of pages6
ISBN (Electronic)0262511126, 9780262511124
StatePublished - 2000
Event17th National Conference on Artificial Intelligence, AAA1 2000 - Austin, United States
Duration: Jul 30 2000Aug 3 2000

Publication series

NameProceedings of the 17th National Conference on Artificial Intelligence and 12th Conference on Innovative Applications of Artificial Intelligence, AAAI 2000


Conference17th National Conference on Artificial Intelligence, AAA1 2000
Country/TerritoryUnited States

Bibliographical note

Publisher Copyright:
Copyright © 2000, American Association for Artificial Intelligence ( All rights reserved.


  • constraint saitsfaction
  • knowledge representation
  • logic programming
  • nonmonotonic reasoning
  • search

ASJC Scopus subject areas

  • Artificial Intelligence
  • Software


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