anchor.diff:  inferred_bif_type(ceil, [_]) -> number;
   inferred_bif_type(float, [_]) -> number;
   inferred_bif_type(floor, [_]) -> number;
  +inferred_bif_type(hd, [_]) -> cons;
  +inferred_bif_type(length, [_]) -> list;
  +inferred_bif_type(map_size, [_]) -> map;
   inferred_bif_type(round, [_]) -> number;
   inferred_bif_type(trunc, [_]) -> number;
  +inferred_bif_type(tl, [_]) -> cons;
   inferred_bif_type(tuple_size, [_]) -> #t_tuple{};
   inferred_bif_type(_, _) -> any.
   
  
positive.code:         _ ->
              t_atom(false)
      end;
  type(put_list, _Args, _Ts, _Ds) ->
      cons;
  type(put_tuple, Args, _Ts, _Ds) ->
  
negative.code: bif_type(is_map_key, [_,_]) -> t_boolean();
  bif_type(length, [_]) -> t_integer();
  bif_type(map_size, [_]) -> t_integer();
  bif_type(node, []) -> #t_atom{};
  bif_type(node, [_]) -> #t_atom{};
  bif_type(round, [_]) -> t_integer();
  bif_type(size, [_]) -> t_integer();
  bif_type(trunc, [_]) -> t_integer();
  