DFKI Research Report-92-03



Language: English

by Harold Boley

Extended Logic-plus-Functional Programming

28 Pages


Extensions of logic and functional programming are integrated in RELFUN. Its valued clauses comprise Horn clauses (`true'-valued) and clauses with a distinguished `foot' premise (returning arbitrary values). Both the logic and functional components permit LISP-like varying-arity and higher-order operators. The DATAFUN sublanguage of the functional component is shown to be preferable to relational encodings of functions in DATALOG. RELFUN permits non-ground, non-deterministic functions, hence certain functions can be inverted using an `is'-primitive generalizing that of PROLOG. For function nestings a strict call-by-value strategy is employed. The reduction of these extensions to a relational sublanguage is discussed and their WAM compilation is sketched. Three examples (`serialise', `wang', and `eval') demonstrate the relational/functional style in use. The list expressions of RELFUN's LISP implementation are presented in an extended PROLOG-like syntax.

This document is available as PDF-File(30,4MB).

The next abstract is here, and the previous abstract is here.

DFKI-Bibliothek (bib@dfki.uni-kl.de)

Note: This page was written to look best with CSS stylesheet support Level 1 or higher. Since you can see this, your browser obviously doesn't support CSS, or you have turned it off. We highly recommend you use a browser that supports and uses CSS, and review this page once you do. However, don't fear, we've tried to write this page to still work and be readable without CSS.