摘要: Publisher Summary This chapter discusses that constraint reasoning involves various types of techniques to tackle the inherent intractability problem satisfying a set constraints. Constraint propagation is one those techniques. It central process solving and indispensable for reasoning. The examines embeds any reasoning, which consists in explicitly forbidding values or combinations some variables problem, because given subset its constraints cannot be satisfied otherwise. this concept shows most accomplished form. There no other field appears such variety forms, characteristics have been analyzed. reviews it formalizes all approaches within unifying framework main existing propagation.