private void AddSubstring(List<int> substring_list)
{
if (_debug) Console.Write("Final ST#: " + _final_string_list.Count + " Add TS: ");
TextString ts = new TextString();
for (int i = 0; i < substring_list.Count; i++)
{
ts.AddChar(_char_list[substring_list[i]]);
_char_list[substring_list[i]].included = true;
if (_debug) Console.Write(substring_list[i] + " ");
}
_final_string_list.Add(ts);
if (_debug) Console.WriteLine();
}