which material is of the same class as amalgam?
Entity Entity Entity Entity Entity Entity Entity
m.025rw19 m.06qqb m.01brf m.025rsfk m.027vj2v m.025sqz8 m.01504
Iron Steel Bronze Copper Aluminium Zinc brass
class class entity
engineering.material engineering.material m.02w4cxr
engineering.material engineering.material engineering.material
Material Material Amalgam
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.02w4cxr } 
?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.02w4cxr)))