Domain (Constraint Satisfaction)

Definition

Domain (Constraint Satisfaction)

A domain $D$ of a constraint satisfaction problem is the non-empty set of values that may be assigned to its variables. For a variable set $V$, an assignment has the form

$$f:V\to D.$$

Every constraint relation of arity $r$ is a subset $R\subseteq D^r$, so it specifies which $r$-tuples of domain values are permitted.