TOWARDS A PROGRAMMING ENVIRONMENT FOR LARGE PROLOG PROGRAMS.

The authors discuss two issues of programming in-the-large in Prolog: modularization and system evolution. A mechanism is proposed which controls both module interactions and programmer's actions. In this way, certain invariants of a large Prolog program can be maintained not only during a single execution, but also throughout the lifetime of the program. Traditional constructs, such as scope rules and modules can be modeled in the proposed framework. Moreover, various kinds of managerial policies in software projects can be enforced. An experimental programming environment, incorporating these ideas, called Elog, has been implemented (in Prolog).