the mouse was invented by which person?
Entity
m.027_g
Douglas Engelbart
class entity
law.inventor m.020lf
law.inventor law.us_patent
Inventor Mouse
none none
law.inventor.us_patents
Patents
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 :law.inventor . 
VALUES ?x1 { :m.020lf } 
?x0 :law.inventor.us_patents ?x1 . 
FILTER ( ?x0 != ?x1  )
}
}
(AND law.inventor (JOIN law.inventor.us_patents m.020lf))