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.

Abstract: A knowledge system has a hierarchical knowledge base comprising a functional decomposition of a set of elements into subsets over a plurality of hierarchical levels, a plurality of predefined functions or conditions of the elements within the subsets of a plurality of the hierarchical levels, and a predefined set of operations to perform on a user-defined set of elements responsive to the functional knowledge base. Preferably, the knowledge base is defined declaratively by assigning parent sets to offspring subsets to define the hierarchy, by indicating the conditions of the subsets which satisfy the predefined functions and by writing task blocks in an imperative language defining the sequence of operations to perform on the user-defined set of elements. Preferably the operations include matching, configuring and expanding the user-defined set of elements into the defined subsets of individual elements and evaluating the predefined functions, and the operations are executed recursively.