Question: who designed a bipropellant rocket engine with liquid hydrogen and gas-generator cycle?
Topic entities:
Gas-generator cycle: m.04qqvv
Liquid hydrogen: m.0g0nz
Logical form: (AND spaceflight.rocket_engine_designer (JOIN spaceflight.rocket_engine_designer.rocket_engines (AND (JOIN (R spaceflight.rocket_engine_cycle.rocket_engines) m.04qqvv) (JOIN (R spaceflight.rocket_engine_fuel.rocket_engines) m.0g0nz))))
Actions:
get_relations(m.04qqvv)
get_neighbors(m.04qqvv,spaceflight.rocket_engine_cycle.rocket_engines)
get_relations(m.0g0nz)
get_neighbors(m.0g0nz,spaceflight.rocket_engine_fuel.rocket_engines)
intersection(#0,#1)
get_relations(#2)
get_neighbors(#2,spaceflight.rocket_engine.designed_by)
Answer:
answer_argument: m.04zgxk
entity_name: Aerojet
answer_argument: m.01vhl6
entity_name: Rocketdyne