Structured document display system

A structured document display system for displaying a correspondence relationship between a first structured document containing a plurality of documents in a hierarchical relationship and a second structured document containing a plurality of documents in a hierarchical relationship, comprising:

• a receiver configured to receive input of a user;
• a display configured to display an image indicating the correspondence relationship between the first structured document and the second structured document;
• and
• a display controller configured to control the display,
• wherein
• the image includes a first area disposed on one side of the image in the left-right direction and displaying at least a part of the plurality of documents included in the first structured document, and a second area disposed on the other side of the image in the left-right direction and displaying at least a part of the plurality of documents included in the second structured document,
• the receiver includes a mouse,
• when the receiver receives input from the user to scroll the image up or down in a case where a mouse pointer associated with the mouse overlaps one of the first area and the second area,
• the display controller controls the display to scroll the document displayed in one of the first area and the second area, and
• the display controller controls the display to display a correspondence relationship related to documents displayed on the image for a predetermined period of time or longer.