QUASI-METRICS AND THE SEMANTICS OF LOGIC PROGRAMS

Article type: Research Article

Authors: Seda, Anthony Karel

Affiliations: Department of Mathematics, University College, Cork, Ireland, e-mail: aks@bureau.ucc.ie

Abstract: Quasi-metrics have been used in several places in the literature on domain theory and the formal semantics of programming languages. In this paper, we consider the role of quasi-metrics in the fixed point semantics of logic programs, examining in detail a quite general process by which fixed points of immediate consequence operators can be found. This work takes as its starting point: (i) Fitting's recent application of the Banach contraction mapping theorem in logic programming; (ii) a theorem of Rutten which generalizes both the contraction mapping theorem and the Knaster-Tarski theorem; (iii) Smyth's work on totally bounded spaces and compact ordered spaces as domains of computation. Our results therefore are theoretical and to be viewed as a contribution to the mathematical foundations of computer science.

DOI: 10.3233/FI-1997-291205

Journal: Fundamenta Informaticae, vol. 29, no. 1-2, pp. 97-117, 1997