anchor.diff:    SignBit: Integer;
     Comparison: Integer;
   begin
  -  if Pointer(Left.FData) = nil then
  +  if not Assigned(Left.FData) then
     begin
       ShallowCopy(Right, Result);
       Exit;
     end
  -  else if Pointer(Right.FData) = nil then
  +  else if not Assigned(Right.FData) then
     begin
       ShallowCopy(Left, Result);
       Exit;
  
positive.code:   See BigIntSpeedTest.dpr
  }
  
  interface
  
  uses
  
negative.code:     {$ENDIF CPU64BITS}
    {$ELSE !PUREPASCAL}
      {$IFDEF CPU64BITS}                                          // 64A  = 64 bit, Assembler
        KaratsubaThreshold             =   96;    // Checked
        ToomCook3Threshold             =  256;    // Checked
        BurnikelZieglerThreshold       =  160;    // Checked
        BurnikelZieglerOffsetThreshold =   80;    // Unchecked
        KaratsubaSqrThreshold          =  256;    // Unchecked
  