Adding rule-based techniques to procedural languages

ABSTRACT

The world of software for applications in industry is dominated by compiled, algebraic (Algol derivative) programming languages such as C, Pascal, and PL/I. One approach to popularizing expert systems techniques in the industrial environment is to integrate software techniques appropriate for expert systems development into algebraic programming languages. While programmers in industry seek more powerful software tools, generally they do not want to give up existing capabilities in order to gain access to new techniques. Thus the question becomes how to integrate expert system techniques into a procedural language so that important characteristics of the procedural language are preserved. YES/LI (Yorktown Expert System / Language One) is an experimental tool for developing expert systems that is an integration of PL/I with data-driven rules. This paper reviews a number of technical issues encountered in the development of YES/LI. The achieved resolution of these issues establishes that rule-based techniques intended for use in large, industrial expert systems can be integrated into the standard features of an existing, algebraic programming language without reducing the functionality of the underlying, procedural language. Features of YES/LI include: condition-action rules with support for both highly expressive conditions and complex actions, PL/I as a subset, block structuring including recursively invoked blocks of rules, support for large blocks of rules written in several source code files, the same access to data bases and routines written in other languages as found in PL/I, excellent performance, portability across several operating systems and computer architectures, the ability for YES/LI routines to be linked, loaded, started, and called just as PL/I routines.

REFERENCES

• 9370 Configurator: "IBM KnowledgeTool: Applying expert systems technology to develop the 9370 Configurator" iBM Corporation, Order Number GK20-2286-00, November 1987.
• OPS5 Book: Lee Brownston , Robert Farrell , Elaine Kant , Nancy Martin, Programming expert systems in OPS5: an introduction to rule-based programming, Addison-Wesley Longman Publishing Co., Inc., Boston, MA, 1985
• OPS5: C. L. Forgy, "OPS5 User's Manual," CMU-CS-81-135, Dept. of Computer Science, Carnegie-Mellon University, July, 1981.
• OPS83: "OPS83 Report - System Version 2," Production Systems Technologies, Inc., Pittsburgh, 1984.
• PL/I: "OS PL/I Version 2, Programming: I2nguage Reference," IBM Corporation, Order Number SC26-4308-0, December 1987.
• RETE: C. L. Forgy, "RETE: A Fast Algorithm for the Many Pattern/Many Object Pattern Match Problem," Artificial Intelligence, pages 19-37, Volume 19, Number 1, September, 1982.
• RETE with Update: M. i. Schor, T. P. Daly, H. S. Lee, B. R. Tibbitts, "Advances in RETE Pattern Matching," Proceedings of the 1986 National Conference on Artificial Intelligence, 1986.
• YES/L1: K.R. Milliken, A.V. Cruise, R.L. Ennis, J.L. Hellerstein, M.J. Masullo, M. Rosenbloom, H.M. Van Woerkom. "YES/Li: A Language for Implementing Real-Time Expert Systems." IBM Research Report, RCI1500, December 1985.
• YES/L1: A. Cruise, R. Ennis, A. Finkel, J. HeUerstein, D. Loeb, M. Masullo, K. Mill/ken, H. Van Woerkom, N. Waite, "YES/LI: Integrating Rule-Based, Procedural, and Real-Time Programming for Industrial Applications," Proceedings of the Third IEEE Conference on Artificial Intelligence Applications, February, 1987.
• YES/MVS: K. R. Milliken, A. V. Cruise, R. L. Ennis, A. J. Finkel, J. L. Hellerstein, D. J. Loeb, D. A. Klein, M. J. Masullo, H. M. Van Woerkom, N. B. Waite, "YES/MVS and the Automation of Operations for Large Computer Complexes," iBM Systems Journal, pages 159-180, Volume 25, Number 2, 1986.

INDEX TERMS

Primary Classification:
  I. Computing Methodologies
  I.2 ARTIFICIAL INTELLIGENCE
      I.2.1 Applications and Expert Systems
          Subjects: Industrial automation

Additional Classification:
  D. Software
  D.2 SOFTWARE ENGINEERING
        D.2.10 Design**
            Subjects: Methodologies**
      D.2.2 Design Tools and Techniques
          Subjects: Structured programming**
  D.3 PROGRAMMING LANGUAGES
      D.3.2 Language Classifications

          Nouns: PL/I
      D.3.4 Processors
          Subjects: Compilers

  I. Computing Methodologies
  I.2 ARTIFICIAL INTELLIGENCE
      I.2.5 Programming Languages and Software
          Subjects: Expert system tools and techniques

  K. Computing Milieux
  K.6 MANAGEMENT OF COMPUTING AND INFORMATION SYSTEMS
      K.6.3 Software Management
          Subjects: Software development

General Terms:
Design, Languages, Management