Varieties of constraints Unary constraints involve a single variable, e.g,SA卡green Binary constraints involve pairs of variables, e.g,SA≠WA Higher-order constraints involve 3 or more variables, e.g.,cryptarithmetic column constraints Preferences(soft constraints),e.g.,red is better than green often representable by a cost for each variable assignment constrained optimization problems Chapter 5 8 Varieties of constraints Unary constraints involve a single variable, e.g., SA 6= green Binary constraints involve pairs of variables, e.g., SA 6= WA Higher-order constraints involve 3 or more variables, e.g., cryptarithmetic column constraints Preferences (soft constraints), e.g., red is better than green often representable by a cost for each variable assignment → constrained optimization problems Chapter 5 8