24. A software shell as claimed in claim 23 wherein each object has attributes and each attribute has at least one value, the database including a hash table and a plurality of pointers for linking the objects and corresponding attributes and values.
24. A software shell as claimed in claim 23 wherein each object has attributes and each attribute has at least one value, the database including a hash table and a plurality of pointers for linking the objects and corresponding attributes and values. 25. A software shell as claimed in claim 24 wherein the means for executing includes means for interrupting execution of a lower priority knowledge source and executing a higher priority knowledge source in accordance with the knowledge source priority scheme.