user: Question: What is the entrant earlier than 1956 with a Vanwall Special chassis?
Columns: ['Year', 'Entrant', 'Chassis', 'Engine', 'Points']
Types: ['real', 'text', 'text', 'text', 'real']
Sample row: [1952.0, 'HW Motors', 'HWM 52', 'Alta', 0.0]
SQL:

assistant: SELECT "Entrant" FROM "Table" WHERE "Year" < 1956.0 AND "Chassis" = 'Vanwall Special';