Outline-processor taking program structure into account

An outline-processor that surrounds each program constituted from a plurality of programs by a respective frame having diagram-displays that connect the frames by a line, such that if the inside of the frame is clicked by a mouse, a source of the program therein is outline-displayed. Diagram-displays display respective arguments of the programs in the vicinity of the frames of the programs and display frame lines of the program thick before expansion and thin after expansion to change the thicknesses of the frame lines of the program before and after expansion. Further, when the plurality of programs are outline-displayed in a plural number, a newest outline-display is displayed in front.