- X is a set of variables {
*x*_{1},...,*x*_{n}} - D = {
*D*_{1},...,*D*_{n}} is a set of associated domains for all*x*_{i}X - C is a set of constraints

The first two elements of the triple have a special meaning because they are the first thing we have to think about when modeling a constraint problem. These two sets X, D can be defined as the viewpoint of a problem, presented next.

Andreas Rossberg 2006-08-28