8. A computer readable storage medium encoded with a computer program that is operable with a data processing system for causing the data processing system to execute: first processing for inputting a natural language sentence and performing morpheme analysis on the natural language sentence; second processing for performing syntactic analysis on the natural language sentence after morpheme analysis and further performing semantic analysis on the natural language sentence; and third processing for converting the natural language sentence after syntactic analysis and semantic analysis into an inquiry sentence described in an ontology description language by referring to a case frame ontology dictionary in which are stored information indicating to which property in an ontology does a relationship among a predicate, a subject and an object in the natural language sentence correspond, wherein said third processing includes: processing for examining, on the basis of said case frame ontology dictionary, a property to which a predicate of said natural language sentence processed by the syntactic analysis and the semantic analysis corresponds and a case frame to which the natural language sentence corresponds; and processing for generating said inquiry sentence by describing the obtained property and case frame in said ontology description language.
8. A computer readable storage medium encoded with a computer program that is operable with a data processing system for causing the data processing system to execute: first processing for inputting a natural language sentence and performing morpheme analysis on the natural language sentence; second processing for performing syntactic analysis on the natural language sentence after morpheme analysis and further performing semantic analysis on the natural language sentence; and third processing for converting the natural language sentence after syntactic analysis and semantic analysis into an inquiry sentence described in an ontology description language by referring to a case frame ontology dictionary in which are stored information indicating to which property in an ontology does a relationship among a predicate, a subject and an object in the natural language sentence correspond, wherein said third processing includes: processing for examining, on the basis of said case frame ontology dictionary, a property to which a predicate of said natural language sentence processed by the syntactic analysis and the semantic analysis corresponds and a case frame to which the natural language sentence corresponds; and processing for generating said inquiry sentence by describing the obtained property and case frame in said ontology description language. 10. The computer readable storage medium encoded with the computer program according to claim 8 , wherein, in said second processing, said computer is made to execute processing for decomposing the natural language sentence on the basis of relationships among a predicate included in said natural language sentence, a nominative case related to the predicate, and an objective case which is a word acting on the nominative case.