#### 34.2.1 Posting Constraints

A constraint is called as any other Prolog predicate. When
called, the constraint is posted to the store. For example:

| ?- `X in 1..5, Y in 2..8, X+Y #= T.`
X in 1..5,
Y in 2..8,
T in 3..13
| ?- `X in 1..5, T in 3..13, X+Y #= T.`
X in 1..5,
T in 3..13,
Y in -2..12

Note that the answer constraint shows the domains of nonground
query variables, but not any constraints that may be
attached to them.