which rocket engine uses an oxidizer of nitric acid and has a chamber pressure of less than 47.0?
(AND spaceflight.bipropellant_rocket_engine (AND (JOIN spaceflight.bipropellant_rocket_engine.oxidizer m.05fmf) (lt spaceflight.bipropellant_rocket_engine.chamber_pressure 47.0^^http://www.w3.org/2001/XMLSchema#float)))