An integrated circuit stores a module that executes applications that play digital streams. When the module is executed, the integrated circuit generates package information by merging files recorded on a first recording medium and a second recording medium, in accordance with merge management information, detects a plurality of playable titles from the package information, and selects one of the detected titles as a current title. The integrated circuit executes the application associated with the current title, and the executed application makes a request to update the generated package information by specifying new merge management information. The integrated circuit changes a file referenced from the newly specified merge management information to read-only before updating the package information, and at a point at which digital stream playback stops due to a current title change, the integrated circuit generates new package information by combining files recorded on the first and second recording media, in accordance with the newly specified merge management information.