which football player plays the center forward position(s)?
Entity Entity
m.01ytpp m.0jl1glj
Kevin Keegan Jim Power
class entity
soccer.football_player m.02wjq8g
soccer.football_player soccer.football_position
Football player Center forward
none none
soccer.football_player.position_s
Position(s)
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 :soccer.football_player . 
VALUES ?x1 { :m.02wjq8g } 
?x0 :soccer.football_player.position_s ?x1 . 
FILTER ( ?x0 != ?x1  )
}
}
(AND soccer.football_player (JOIN soccer.football_player.position_s m.02wjq8g))