PURPOSE: To make possible the simple and rapid entry of rules by calculating ruled line data based on the type of entered decorative rules and the start and end points of decorative rules, and calculating type data based on element codes from a decorative rule element arrangement storage device and ruled line data.

CONSTITUTION: When decorative rule data is entered, data on the type, start and end points of decorative rule is entered from an input device 20. This data is supplied to a ruled line data arithmetic and logic operation device 24 to calculate appropriate ruled line data for the preparation of type data. A type data arithmetic and logic operation device 28 calculates and outputs type data based on the ruled line data, and element code arrangement data stored in a decorative rule element arrangement storage device 26. In addition, a display control device 30 outputs a display signal based on the type data. A display device 32 receives this display signal and display decorative rules. Data entered from the input device 20 can be supplied to a type data arithmetic and logic operation device 28 directly for operation. A registered data arithmetic and logic operation device 22 registers any decorative rule data in the decorative rule element arrangement storage device 26.