DEVICES FOR INTERPRETING AND RETRIEVING XML DOCUMENTS, METHODS OF INTERPRETING AND RETRIEVING XML DOCUMENTS, AND COMPUTER PRODUCT

A device includes a section to input retrieval conditions, a section that judges whether documents-structure data arranged according to a tree structure in an order of appearance of elements in XML documents matches with corresponding one of the retrieval conditions input, a section that extracts character string in character-string data associated with documents-structure data, which matches with the retrieval conditions, and a section that judges whether the character string extracted matches with the retrieval conditions.