Question: What is the official website for the association football club headquartered in Alkmaar?
Choices:
http://www.anotherworld.fr/anotherworld_uk
https://dur.ac.uk
https://www.2k.com/
http://www.appstate.edu/
http://www.egofilmarts.com/
http://www.lexingtonky.gov
http://www.az.nl/
http://www.hds.harvard.edu/
https://www.apple.com/au/ios/
http://arunachalpradesh.gov.in/
Answer: http://www.az.nl/
SPARQL: SELECT DISTINCT ?pv WHERE { ?e <pred:instance_of> ?c . ?c <pred:name> "association football club" . ?e <headquarters_location> ?e_1 . ?e_1 <pred:name> "Alkmaar" .  ?e <official_website> ?pv .  }
Program:
function: Find
inputs: Alkmaar
function: Relate
dependencies: 0
inputs: headquarters location
backward
function: FilterConcept
dependencies: 1
inputs: association football club
function: QueryAttr
dependencies: 2
inputs: official website