anchor.diff:  
   constructor TmFormulaField.Create;
   begin
  -  FDataType:= vftUnknown;
  +  FDataType:= fftFloat;
     FSize := 0;
     FName := '';
     FOnChangeName:= nil;
  
positive.code:     function Count : integer;
      function Get (const aIndex : integer) : TmFormulaField;
      function FindByName (const aName : string) : TmFormulaField;
    end;
  
  implementation
  
  uses
    sysutils;
  
  { TmFormulaFields }
  
  
negative.code: interface
  
  uses
    Classes, contnrs, db,
    mVirtualFieldDefs, StrHashMap;
  
  type
  
    TmFormulaFieldType = (fftFloat, fftString, fftDateTime);
  
    { TmFormulaField }
  
    TmFormulaField = class
    strict private
      FDataType : TmFormulaFieldType;
      FSize : integer;
      FFormula : String;
      FName : string;
  