We define a semantics for negation as failure in logic programming. Our semantics may be
viewed as a cross between the approaches of Clark [5] and Fitting [7]. As does [7], our …

The purpose of semantic query optimization is to use semantic knowledge (eg, integrity
constraints) for transforming a query into a form that may be answered more efficiently than …

This paper describes the organization of the CENTAUR system and its main components.
The system is a generic interactive environment. When given the formal specification of a …

Early software environments have supported a narrow range of activities (programming
environments) or else been restricted to a single “hard-wired” software development …

This textbook is an introduction to denotational semantics and its applications to
programming languages. Dr Allison emphasizes a practical approach and the student is …

Anti-unification guarantees the existence of a term which is an explicit representation of the
most specific generalization of a collection of terms. This provides a formal basis for learning …

This is the Reference Manual for the Ciao Prolog development system. It contains basic
information on how to install Ciao Prolog and how to write, debug, and run Ciao Prolog …

As a logic programming language, PROLOG is deficient in two areas: negation and control
facilities. Unsoundly implemented negation affects the correctness of programs and poor …

We briefly discuss the shortcomings of negation in conventional Prolog systems. The design
and implementation of the negation constructs in NU-Prolog are then presented. The major …

Abstract An interactive Prolog debugger, Dewlap, is described. Output from the debugger is
in the form of graphical displays of both the derivation tree and the parameters to procedure …