Patent ID: 7333970

Claim:
A data processing system, comprising: a) a database; b) a computer unit for generating an ontology comprising a class structure that defines the structure of data stored in said database, and a declarative system of rules, wherein the rules combine elements of the class structure and/or data; c) an input/output unit for inputting a query to retrieve data from said database and for outputting data responsive to the query; and d) a first inference unit in which the rules are evaluated for generating an answer to the query; wherein: e) the first inference unit is associated with an evaluation unit, which comprises a second inference unit; f) within the second inference unit an explanation of the answer to the query is generated by evaluating predefined explanation rules; g) inference protocols are read into the evaluation unit, which state, which rules were evaluated for answering the query, and which contain the facts, which were used for instantiation of the rules for answering the query; and h) the inference protocols form instances of the explanation rules.