Algernon for Expert Systems

Benjamin Kuipers
Computer Science Department
University of Texas at Austin
Austin, Texas 78712 USA

18 January 1994

Abstract:

This is a DRAFT document, showing how to express various kinds of useful inference in Algernon.

• Contents
• Introduction to Frame Based Knowledge Representation
  • Frames
  • Frames and Their Names
  • Frames and Predicate Calculus
  • Access Paths
  • Rules Are Implications
  • Inference in Algernon
• Example: Frames, Access Paths, and Retrieval by Description
  • Calling Algernon from Lisp
  • The Structure of an Algernon Theory
  • Taxonomy
  • Slots Represent Relations
  • Rules Specify Inferences
  • Facts Tell the Story
  • Questions: Checking for Understanding
• Example: Forward- and Backward-Chaining Inference
  • Taxonomy
  • Slots
  • Rules
  • Facts
  • Queries
• A Simple Expert System: Does John Have The Flu?
  • Taxonomy and Slots
  • Rules - Simple
  • Queries Based on Simple Rules
  • Rules - Slightly Less Simple
  • Queries - Slightly Less Simple Rules
• Calling Lisp and the User from Algernon
  • Evaluating Lisp Expressions
  • Returning Values from Lisp to Algernon
  • The List of Values in a Slot
  • Requesting Information from the User
• Sequencing Methods
  • Access Path Sequence
  • Block-to-Block Sequence
  • Counters
• Unwritten Sections
• About this document ...