how to generate relationship between two enumerate with double cycle

Thanks a lot in advance . trouble in how to generate relationship between two enumerate .

%-------------------------------
enum weeks = {w1,w2,w3,w4};

array[weeks] of 1..10 : weekShiftQty = [4,5,7,4]; % total shift = 20

enum shift = _(1..20);

array[shift] of weeks : shiftWeek = [ % how to generate shiftWeek relationship %

  % just like following : calculate shift belog to which week base on weekShiftQty
  % shiftWeek[1] = w1 , ... , shiftWeek[4] = w1 , 
  % shiftWeek[5] = w2 ,...  , shiftWeek[9] = w2 ,
  % shiftWeek[10] = w3 ,...  , shiftWeek[16] = w3 ,
  % shiftWeek[17] = w4 ,...  , shiftWeek[20] = w4 ,
  | s in shift
];

%-------------------------------

Here's a solution, i.e. using [ w | w in weeks, _ in 1..weekShiftQty[w]] to generate the shiftWeek array:

enum weeks = {w1,w2,w3,w4};
array[weeks] of 1..10 : weekShiftQty = [4,5,7,4]; % total shift = 20
enum shift = _(1..20);

array[shift] of weeks: shiftWeek = [
                                     w
                                     | w in weeks,
                                       _ in 1..weekShiftQty[w]
                                     ];
output [
        "shiftWeek: \(shiftWeek)\n"
        ];

The output is

shiftWeek: [w1, w1, w1, w1, w2, w2, w2, w2, w2, w3, w3, w3, w3, w3, w3, w3, w4, w4, w4, w4]