Determining copyright information based on overlapping information between portions of two documents

Abstract

A document management system is provided to manage electronic documents in connection with copyrights. Herein, copyright management information is set with respect to a constituent element of a document that a user produces. The constituent element corresponds to a chapter, a paragraph, a sentence, a figure or a table, for example. The copyright management information represents copyright information regarding the use of the document, which is classified into prescribed levels such as a reference level, a copy level and a print level. In addition, it represents prescribed conditions as to whether the use of the document is allowed with payment of fee, with filing of application and with display of copyright or not, for example. Further, the content of the copyright management information can be changed in response to user levels respectively. The copyright management information is connected with information representing the constituent element. When the user requests to use a prescribed portion of another document other than the document that the user is presently producing, a use-allowed part is determined within the prescribed portion on the basis of the copyright management information of the constituent element overlapping with the prescribed portion. So, the user is capable of making a decision whether to actually use the use-allowed part in consideration of the prescribed conditions.