what are the ships in the class cruise.
Entity Entity Entity Entity Entity
m.0xn9y9r m.0vsgpcj m.0nfvttq m.0j29yv7 m.0h962y8
MV Britannia American Star Mstislav Rostropovich Star Flyer Royal Princess
class entity
boats.ship m.01tq2l
boats.ship boats.ship_class
Ship cruise
none none
boats.ship.ship_class
Ship Class
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> PREFIX : <http://rdf.freebase.com/ns/> 
SELECT (?x0 AS ?value) WHERE {
SELECT DISTINCT ?x0  WHERE { 
?x0 :type.object.type :boats.ship . 
VALUES ?x1 { :m.01tq2l } 
?x0 :boats.ship.ship_class ?x1 . 
FILTER ( ?x0 != ?x1  )
}
}
(AND boats.ship (JOIN boats.ship.ship_class m.01tq2l))