A declarative environment for concurrent logic programming

Abstract

A logic programming environment should provide users with declarative control of program development and execution and resource access and allocation. It is argued that the concurrent logic language PARLOG is well suited to the implementation of such environments. The essential features of the PARLOG Programming System (PPS) are presented. The PPS is a multiprocessing programming environment that supports PARLOG (and is intended to support Prolog). Users interact with the PPS by querying and updating collections of logic clauses termed data bases. The PPS understands certain clauses as describing system configuration, the status of user deductions and the rules determining access to resources. Other clauses are understood as describing meta relationships such as inheritance between data bases. The paper introduces the facilities of the PPS and explains the essential structure of its implementation in PARLOG by a top down development of a PARLOG program which reads as a specification of a multiprocessing operating system.