7. A document type determining method for determining an inclusive relationship of a document type by determining a possible structure of a structured document, comprising: a document type inputting step for designating the first document type and the second document type which are to be compared; a finite-state automaton constructing step for constructing finite-state automatons from content models defining lower elements which can be included in elements in the first and second document types, respectively; a finite-state automaton collating step for determining whether a language received by the finite-state automaton constructed from the first document type is included in a language received by the finite-state automaton constructed from the second document type, the two finite-state automatons being constructed from the elements of the same name in the first and second document types, respectively; and a document type collating step for determining the presence or absence of the inclusive relationship by checking whether an element of the same name as the element in the first document type exists in the second document type and the language defined by the element in the first document type is included in the language defined by the element of the second document style.
7. A document type determining method for determining an inclusive relationship of a document type by determining a possible structure of a structured document, comprising: a document type inputting step for designating the first document type and the second document type which are to be compared; a finite-state automaton constructing step for constructing finite-state automatons from content models defining lower elements which can be included in elements in the first and second document types, respectively; a finite-state automaton collating step for determining whether a language received by the finite-state automaton constructed from the first document type is included in a language received by the finite-state automaton constructed from the second document type, the two finite-state automatons being constructed from the elements of the same name in the first and second document types, respectively; and a document type collating step for determining the presence or absence of the inclusive relationship by checking whether an element of the same name as the element in the first document type exists in the second document type and the language defined by the element in the first document type is included in the language defined by the element of the second document style. 9. The method according to claim 7, wherein a specific element name which represents a target to be determined is inputted in the document type inputting step and an inclusive relationship between a language defined by the element in the first document type and a language defined by the element in the second document type is determine with respect to only the specific clement name as a target.