Constraint domain
= Constraint domain
{title2=$D_i$}
The <set> of values permitted for a variable $X_i$ in a <constraint satisfaction problem>. All assignments before relational constraints form the <Cartesian product> $\prod_iD_i$, whose <cardinality> is $\prod_i|D_i|$ for finite domains. Unary restrictions can be incorporated directly into the <constraint domain> by deleting forbidden values.