% 
% Global constraint domain_constraint in MiniZinc.
% 
% From Global Constraint Catalogue
% http://www.emn.fr/x-info/sdemasse/gccat/sec4.103.html
% """
% domain_constraint​(VAR,​VALUES)
% 
% Purpose
%
% Make the link between a domain variable VAR and those 0-1 variables 
% that are associated with each potential value of VAR: The 0-1 variable 
% associated with the value that is taken by variable VAR is equal to 1, 
% while the remaining 0-1 variables are all equal to 0.
%
% Example
%     (
%     5, <
%     var01-0 value-9,
%     var01-1 value-5,
%     var01-0 value-2,
%     var01-0 value-7
%     >
%     )

%  The domain_constraint holds since VAR=5 is set to the value corresponding to the 0-1 variable set to 1, while the other 0-1 variables are all set to 0.

% """


% This MiniZinc model was created by Hakan Kjellerstrand, hakank@bonetmail.com
% See also my MiniZinc page: http://www.hakank.org/minizinc
%

% include "globals.mzn"; 
int: n = 4;
array[1..n] of var 0..1: var01; % or var bool
array[1..n] of var 1..9: values;
var 1..9: val;

predicate domain_constraint(array[int] of var 0..1: var01, array[int] of var int: values) =
  exists(i in 1..n) (
    var01[i] = 1
    /\
    val = values[i]  
  )
  /\
  sum(var01) = 1

;

solve satisfy;

constraint
  var01 = [0,1,0,0]
  /\
  values = [9,5,2,7]
  /\
  val = 5
  /\
  domain_constraint(var01, values)
;