METHOD AND APPARATUS FOR BUILDING KNOWLEDGE-BASED SYSTEMS

An efficient inherit on store technique for performing inheritance in a modular form caches summary inheritance information at each node or slot in a knowledge representation frame. The functional characteristics of each node is independent of all other nodes so that different types of inheritance information can be interpreted without special concern about the source or inheritance path. To this end, the invention uses a third kind of value besides a local value and an inherited value, herein called a combined value. The combined value according to the invention represents a summary of the subgraph above a given node. Given an adequate summary, the inheritance mechanism according to the invention needs only to consider the local value of a node and the combined value of its immediate parents. From this information, the inheritance mechanism can produce a combined value for local node and can generate an inherited value to be expressed by the local node. The combined value is used by all descendant nodes to generate inherited values for the respective nodes.