anchor.diff:      function Add : TmGroupByDef;
       function Count : integer;
       function Get(const aIndex : integer): TmGroupByDef;
  +    procedure Clear;
     end;
   
     TmCalculationKind = (ckSum, ckCount, ckMin, ckMax, ckFormula);
  
positive.code:   tmpValues : TmSummaryValues;
    summaryValue : TmSummaryValue;
  begin
    FVerticalValues.Clear;
    FHorizontalValues.Clear;
    FRecordCoordinates.Clear;
    FValues.Clear;
  
    for i := 0 to FVerticalGroupByDefs.Count - 1 do
      FVerticalValues.Add;
  
negative.code:     end;
    end;
  
  var
    y, m, d : word;
  begin
    case aGroupByDef.OperationKind of
      gpoDistinct:
  