user: Question: What kind of Entrant has a Maserati Straight-6 Engine, built in the year 1958 or early, and has a Maserati 250F Chassis with points less than 4?
Columns: ['Year', 'Entrant', 'Chassis', 'Engine', 'Points']
Types: ['real', 'text', 'text', 'text', 'real']
Sample row: [1953.0, 'Equipe Gordini', 'Gordini Type 16', 'Gordini Straight-6', 0.0]
SQL:

assistant: SELECT "Entrant" FROM "Table" WHERE "Engine" = 'Maserati Straight-6' AND "Year" < 1958.0 AND "Chassis" = 'Maserati 250F' AND "Points" < 4.0;