steel and what other materials are in the same class?
Entity Entity Entity Entity Entity Entity Entity
m.02w4cxr m.025rw19 m.01brf m.025rsfk m.027vj2v m.025sqz8 m.01504
Amalgam Iron Bronze Copper Aluminium Zinc brass
class class entity
engineering.material engineering.material m.06qqb
engineering.material engineering.material engineering.material
Material Material Steel
none none none
engineering.material.subclass engineering.material.parent_material_class
Child material class Parent material 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 :engineering.material . 
?x1 :type.object.type :engineering.material . 
VALUES ?x2 { :m.06qqb } 
?x1 :engineering.material.subclass ?x0 . 
?x2 :engineering.material.parent_material_class ?x1 . 
FILTER ( ?x0 != ?x1 && ?x0 != ?x2 && ?x1 != ?x2  )
}
}
(AND engineering.material (JOIN (R engineering.material.subclass) (JOIN (R engineering.material.parent_material_class) m.06qqb)))