Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_name_42 (entrant VARCHAR, year VARCHAR, chassis VARCHAR, points VARCHAR)
### Question:
What is the entrant of a chassis maserati 250f, also has 6 points and older than year 1957?
### Answer:
SELECT entrant FROM table_name_42 WHERE chassis = "maserati 250f" AND points = "6" AND year < 1957