Abstract: A Multi-Level Architecture for developing intelligent computer systems composes computational modules uniformly across diverse developmental framework. The modules interact via message passing and are assembled to form application-specific systems. A first level of the Multi-Level Architecture includes a cooperative operating system which provides support for message passing and resource allocation and is preferably based on a module-oriented programming (MOP) model. The first level, for example, defines a virtual machine which is mapped onto an underlying hardware and operating system environment. A second level of the Multi-Level Architecture supports a plurality of application-independent problem-solving frameworks (PSF's) or programming environments for building modules and combining modules of different frameworks into complex systems.

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.