which builder built the ship with draught less than 6.15 and length 80.0?
(AND boats.ship_builder (JOIN (R boats.ship.ship_builder) (AND (JOIN boats.ship.length_overall 80.0^^http://www.w3.org/2001/XMLSchema#float) (lt boats.ship.draught 6.15^^http://www.w3.org/2001/XMLSchema#float))))