
::(?Var, ++Domain, ?Bool)

   Reflect into Bool the truth of Var having the domain Domain.

Arguments
   Var                 (Domain) variable (array notation accepted)
   Domain              Domain specification
   Bool                Reified truth value  (array notation accepted)

Type
   library(gfd)

Description

   Provides a reified form of the ::/2 domain assignment predicate.  This
   reified ::/3 is defined only to work for one variable (unlike ::/2).

   For a single variable, V, the Bool will be instantiated to 0 if the
   current domain of V does not intersect with Domain.  It will be
   instantiated to 1 iff the domain of V is wholly contained within Domain.
   Finally the Boolean will remain a domain variable in the range 0..1, if
   neither of the above two conditions hold.

   Instantiating Bool to 1, will cause the constraint to behave exactly like
   ::/2.  Instantiating Bool to 0 will cause Domain to be excluded from the
   domain of the variable.

   Note that calling the reified form of :: will result in the Variable
   becoming a domain variable, even if Bool is uninstantiated.

   Further note that, like other reified predicates, :: can be used infix in
   a GFD  expression, e.g. B #= (X :: [1..10]) is equivalent to
   ::(X, [1..10], B).



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

Examples
   [eclipse 2]: ::(X, [1..10, 12..30], 1).

X = X{[1 .. 10, 12 .. 30]}


[eclipse 2]: ::(X, [1..10, 12..30], 0).

X = X{[-1000000 .. 0, 11, 31 .. 1000000]}

[eclipse 2]: ::(X, [1..10, 12..30], B).

X = X{[-1000000 .. 1000000]}
B = B{[0, 1]}

[eclipse 2]: gfd:( B #= (X :: [1..10, 12..30])).

B = B{[0, 1]}
X = X{[-1000000 .. 1000000]}



See Also
   suspend : :: / 3, ic : :: / 3, fd : :: / 3, :: / 2
