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# $::(?Vars, ?Range, ?Bool)

Reified pure range constraint
*Vars*
- Variable or number, or a list of variables or numbers
*Range*
- Variable or Lo..Hi, where Lo and Hi are variables or numeric expressions
*Bool*
- Variable, 0 or 1

## Description

Reified version of $::/2, i.e. the truth value of the range constraint is
reflected in the value of the 0/1 variable Bool.
This constraint suspends until its first two arguments are ground.
It then unifies Bool according to the truth value of the corresponding
$::/2 constraint.

Note: as opposed to $::/2, the first argument cannot be a list.

### Modules

This predicate is sensitive to its module context (tool predicate, see @/2).
## Examples

?- $::(X, 1 .. 5, B), X = 3.0.
B = 1
X = 3.0
Yes (0.00s cpu)
% range violated
?- $::(X, 1 .. 5, B), X = 6.
B = 0
X = 6
Yes (0.00s cpu)

## See Also

$:: / 2