
gfd_vars_exclude_domain(+Vars, ?Domain)

   Exclude the values specified in Domain from the domains of Vars.

Arguments
   Vars                Collection of existing domain variables or integers
   Domain              Domain specs or existing domain variable or integer

Type
   library(gfd)

Description


   Primitive for excluding the values specified in Domain from the
   domains of Vars.

   Domain can be a list (note only a list is supported in this
   primitive, and not a collection) of domain specifications, a la the
   domain specifications of (::)/2 -- i.e. each element can be an
   integer, or an integer range in the form Lo..Hi. Alternatively,
   Domain can be an existing GFD domain variable, or an integer. 

   Note that this predicate is intended for use only in implementing
   co-operation with other solvers and constraint propagators at the
   ECLiPSe level, and should not be called from ordinary user code.
   It differs from the usual constraint in that the propagation is not
   performed immediately. Normally, propagation in gecode is performed by
   a suspended goal that is scheduled and woken after each constraint is
   posted.  However, this predicate does not call the woken goal
   scheduler (wake/0), so the propagation goal may not be executed 
   immediately. (It is possible that under some circumstances the goal 
   will be executed, if wake/0 is called indirectly - one example would be
   by the unify handler if the variable becomes ground - but this should not
   be relied upon.) To ensure that the goals are eventually executed, the 
   caller should arrange for wake/0 to be called at some appropriate point 
   in the subsequent execution.  Please see the "Advanced Control Features" 
   section of the User Manual for more information about woken goal 
   management.

   This predicate is specific to lib(gfd). For Gecode, if multiple
   values need to   be excluded from the domain of a variable, it is much more
   efficient to do it in one go, rather than excluding each value 
   individually (e.g. using gfd_vars_exclude/2). Also, if the values
   has to be excluded from multiple variables, it is more efficient to use
   one primitive to do this, rather than exclude the values from each 
   variable individually, as this is done with one event.



Modes and Determinism
   gfd_vars_exclude_domain(+, ?)
   gfd_vars_exclude_domain(+, ++)

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


