A graphical constraint-based production system environment

A novel and effective graphical approach to visually programming rules based on constraints is given. It is shown how constraints can be visualized for rule programming applications and mechanically converted to and from operational tests. User experiments are described that establish the intuitiveness of the pictorial constraint-based rule encodings over a conventional textual language such as OPS-5. A modular rule programming environment architecture is presented that uses an intermediate constraint representation. A working color computer implementation of the visual interface and programming environment is described, and its use is illustrated