Abstract: To help a user program a computer target system to solve problems, the computer system is provided with predefined capabilities and the user is provided with a knowledge system that includes knowledge about applying the capabilities to effectively and efficiently solve the user's problems. The knowledge system provides automatic programming for solving problems within a particular domain, rejects problems that cannot be solved using the available capabilities of the target computer, and explains how and why a certain program was generated or why a program cannot be generated to solve a given problem.

Abstract: A tool is used for knowledge engineers for building and interpreting a knowledge base having separate portions encoding control knowledge, factual knowledge, and judgmental rules. The tool has an inference engine applying the judgmental rules according to a built-in control procedure defining discrete states or control steps during a consultation with a user. The control knowledge is encoded in an applicative and imperative language defining control actions to be executed during interruption of the built-in control procedure at specified control steps. Since the control knowledge is explicit and results in the modification of data only in a precisely defined fashion, the tool can be used to build knowledge systems that can always explain their conclusions and reasoning, and that are intelligible and modifiable.