Computational Logic II
Description
- Project Title:
- Computational Logic II
- Acronym:
- COMPULOG 2
- Number:
- 6810
- Work Area:
- Logics and Logic Programming
- Coordinator:
- SMC/CWI
Kruislaan 413
NL - 1098 SJ AMSTERDAM
- Coordinator Country:
- NL
- Partners
- Katholieke Universiteit Leuven B
ECRC Munich D
RWTH Aachen D
Universität des Saarlands-DFKI D
Universit‡ di Pisa I
Universit‡ di Roma La Sapienza I
Universit‡ di Roma Tor Vergata I
UNINOVA Lisbon P
University of Uppsala S
Imperial College of Science, Technology and Medicine UK
University of Bristol UK
University of Edinburgh UK
- Associate partner
- Université d'Aix Marseille II F
- Contact Point:
- Prof. Dr. K.R. Apt
- Telephone:
- +31/20 5924135
- Fax:
- +31/20 5924199
- E-Mail:
- apt@cwi.nl
- Keywords:
- logic programming, types and objects, non-monotonic reasoning, meta-reasoning, knowledge-base systems
- Start Date:
- 1 August 92
- Duration:
- 36 months
- Status:
- running
- Abstract:
- This project is concerned with the extension of logic programming to improve its knowledge representation and problem-solving capabilities. Three main areas of knowledge representation will be investigated: types and objects, non-monotonic reasoning, and meta-reasoning. The work on problem solving will be concerned with program development and will contribute to knowledge engineering. The project builds on the results of COMPULOG (3012).
AIMS
COMPULOG II has the long term goal of developing the foundations for an integrated, logic-based software environment, including associated software development tools, that deals with all aspects of computing. The language and tools will extend the logic programming paradigm by incorporating enhancements from related paradigms in the areas of databases, artificial intelligence and mathematical logic. COMPULOG II will develop and use the Gödel language developed in COMPULOG to integrate many of the other developments.
APPROACH AND METHODS
The work is organised into four themes. The first two are concerned with extending the expressive power of logic programming and developing methodologies for building applications. Special emphasis will be given to integrating objects and logic in the context of data and knowledge based systems. Work on non-monotonic reasoning will be concerned both with extensions and restrictions of negation as failure, and with its use to formalise common sense reasoning. Special attention will be given to the computational behaviour of such formalisation. Work on meta-reasoning will concentrate on improving the technology for meta-programming and on treating theories (programs, program specifications, databases, and knowledge representations) as objects. The third theme, program development, is concerned with the dynamics of constructing, maintaining and analysing appropriately extended logic programs, program specifications, databases, and knowledge representations. The fourth will implement and integrate appropriate results from COMPULOG, using the Gödel language as a platform for integrating work on types, meta-reasoning and program development, and integrating the same techniques with techniques of non-monotonic reasoning for knowledge base systems. This work will focus on the development of structured knowledge representations and on query evaluation and integrity checking methods. Extensions needed to make logic programming closer to the natural language used in legal documents (types, non-monotonic reasoning, and meta-reasoning) will also be investigated.
PROGRESS AND RESULTS
Types and Objects area
Two approaches towards an integration of object-oriented features with deductive systems have been considered. On the one hand, the deductive OODB system ConceptBase, developed in Aachen, has been enriched by concept language characteristics. On the other hand, more features have been added to concept language in order to make them applicable to practical systems, where ConceptBase has been chosen as a testbed when possible. Both approaches concentrated on procedures for querying knowledge bases and for reasoning about queries.
Non-monotonic and Metareasoning area
Emphasis was placed on the following main research topics:
- analysis of various forms of non-monotonic reasoning, including abduction, belief revision, and counterfactuals,
- computational aspects of non-monotonic reasoning,
- design and semantics of metalevel features, and their applications to various forms of reasoning.
Program Development area
The work has mostly focused on control issues and specification issues. More specifically the following topics were studied for logic programming languages: specification, synthesis and transformation of programs, program analysis, termination, occur-check problem, partial deduction.
Knowledge Base Systems
The ConceptBase deductive object-oriented database was further developed with the aim of using it as a platform for testing the integration of solutions from deductive databases, object-oriented databases, and concept languages. Also the subject of belief revision, dealing with time in deductive databases, and the problem of diagnosis and repair were studied.
Goedel
Both theoretical and practical work was pursued. In particular, ways of efficient implementation of Goedel meta-programming facilities were studied. Also, the problem of emitting code which is as clean as possible (eg does not use the var predicate) was investigated.
Legal Reasoning
The work focused on the interpretation of legal knowledge and its formalisation in declarative systems. A number of extensions of logic programming needed to make it closer to the natural language used in legislation have been identified.
POTENTIAL
The knowledge gained from the research carried out in this project will have an impact on the design of logic-based software environment. The programming language Godel will be a useful tool for declarative programming based on logic programming in which non-monotonic and meta- reasoning can be properly formalised. The deductive object-oriented database system ConceptBase will be a sophisticated tool for database applications.
LATEST PUBLICATIONS
- In the selection below preference was given to publications which appeared or were accepted for publication. Additionally, publications in different areas were selected.
- Hill P M and Lloyd J W The Goedel Programming Language MIT Press Logic Programming Series (to appear)
- Apt and A. Pellegrini K R On the occur-check free Prolog programs, accepted for ACM Toplas
- Donini F M, Lenzerini M, Nardi D and Schaerf A and Nutt W Adding Epistemic Operators to Concept Languages, In: Proc. 3rd International Conference on Principles of Knowledge Representation and Reasoning (1992)
- Pereira L M, Aparicio J N and Alferes J J Non-monotonic Reasoning with Logic Programming Journal of Logic Programming, Special issue on Non-Monotonic reasoning (to appear)
- Jarke M, Jeusfeld M, Miethsam A and Gocek M Towards a logic-based reconstruction of software configuration management, In: Proc. 7th Knowledge-Based Software Engineering Conference KBSE'92, McLean, Virginia (1992)
Sven Müßig, last update 07-nov-1995. Your feedback is welcome.