Logic Programming Applications: What Are the Abstractions and Implementations?

This article presents an overview of applications of logic programming, classifying them based on the abstractions and implementations of logic languages that support the applications. The three key abstractions are join, recursion, and constraint. Their essential implementations are for-loops, fixed points, and backtracking, respectively. The corresponding kinds of applications are database queries, inductive analysis, and combinatorial search, respectively. We also discuss language extensions and programming paradigms, summarize example application problems by application areas, and touch on example systems that support variants of the abstractions with different implementations

A deductive and typed object-oriented language

In this paper we introduce a logical query language extended with object-oriented typing facilities. This language, called DTL (from DataTypeLog), can be seen as an extension of Datalog equipped with complex objects, object identities, and multiple inheritance based on Cardelli type theory. The language also incorporates a very general notion of sets as first-class objects. The paper offers a formal description of DTL, as well as a denotational semantics for DTL programs