A constraint is a relation that should be satisfied; for example, that a line remain horizontal, that a resistor in an electrical circuit simulation obey Ohm's Law, or that the height of a bar in a bar chart be proportional to some number in an application program. Constraints have been used in a variety of languages and systems, particularly user interface toolkits, in planning and scheduling, and in simulation.
Our research is in several areas:
Four screen snapshots of a constraint-based demonstration of a theorem about quadrilaterals. Applet.