which is the bipropellant rocket engine that uses oxidizer of lox and has the chamber pressure of less than 54.0?
(AND spaceflight.bipropellant_rocket_engine (AND (JOIN spaceflight.bipropellant_rocket_engine.oxidizer m.01tm_5) (lt spaceflight.bipropellant_rocket_engine.chamber_pressure 54.0^^http://www.w3.org/2001/XMLSchema#float)))