anchor.diff:  bif(list_to_existing_atom, 1) -> true;
   bif(list_to_float, 1) -> true;
   bif(list_to_integer, 1) -> true;
  +bif(list_to_integer, 2) -> true;
   bif(list_to_pid, 1) -> true;
   bif(list_to_tuple, 1) -> true;
   bif(load_module, 2) -> true;
  
positive.code: bif(concat_binary, 1) -> true;
  bif(date, 0) -> true;
  bif(delete_module, 1) -> true;
  bif(disconnect_node, 1) -> true;
  bif(element, 2) -> true;
  bif(erase, 0) -> true;
  bif(erase, 1) -> true;
  bif(exit, 1) -> true;
  bif(exit, 2) -> true;
  bif(float, 1) -> true;
  
negative.code: bif(halt, 1) -> true;
  bif(hd, 1) -> true;
  bif(integer_to_list, 1) -> true;
  bif(integer_to_list, 2) -> true;
  bif(iolist_size, 1) -> true;
  bif(iolist_to_binary, 1) -> true;
  bif(is_alive, 0) -> true;
  