Models and equality for logical programming

Joseph A. Goguen, José Meseguer

Research output: Chapter in Book/Report/Conference proceedingConference contribution


We argue that some standard tools from model theory provide a better semantic foundation than the more syntactic and operational approaches usually used in logic programming. In particular, we show how initial models capture the intended semantics of both functional and logic programming, as well as their combination, with existential queries having logical variables (for both functions and relations) in the presence of arbitrary user-defined abstract data types, and with the full power of constraint languages, having any desired built-in (computable) relations and functions, including disequality (the negation of the equality relation) as well as the usual ordering relations on the usual built-in types, such as numbers and strings. These results are based on a new completeness theorem for order-sorted Horn clause logic with equality, plus the use of standard interpretations for fixed sorts, functions and relations. Finally, we define “logical programming,” based on the concept of institution, and show how it yields a general framework for discussions of this kind. For example, this viewpoint suggests that the natural way to combine functional and logic programming is simply to combine their logics, getting Horn clause logic with equality.

Original languageEnglish (US)
Title of host publicationTAPSOFT 1987 - Proceedings of the International Joint Conference on Theory and Practice of Software Development
EditorsHartmut Ehrig, Giorgi Levi, Ugo Montanari, Robert Kowalski
Number of pages22
ISBN (Print)9783540176114
StatePublished - 1987
Externally publishedYes
Event2nd International Joint Conference on Theory and Practice of Software Development, TAPSOFT 1987 - Pisa, Italy
Duration: Mar 23 1987Mar 27 1987

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume250 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Other2nd International Joint Conference on Theory and Practice of Software Development, TAPSOFT 1987

ASJC Scopus subject areas

  • Theoretical Computer Science
  • Computer Science(all)


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