Question: What is the official website of the association football club headquartered in Porto (the one whose Dewey Decimal Classification is 2--46915)?
Choices: http://www.escondido.org
http://www.indstate.edu
https://www.fcporto.pt/
http://www.peewee.com/
http://www.carmenelectra.com
http://www.abc.net.au/tv/channels/abc1.htm
http://www.aachen.de/
http://www.xinjiang.gov.cn
http://www.westpoint.edu/
https://www.gov.taipei/
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> "Porto" . ?e_1 <Dewey_Decimal_Classification> ?pv_1 . ?pv_1 <pred:value> "2--46915" . ?e <official_website> ?pv .  }
Program:
function: Find
inputs: Porto
function: FilterStr
dependencies: 0
inputs: Dewey Decimal Classification
2--46915
function: Relate
dependencies: 1
inputs: headquarters location
backward
function: FilterConcept
dependencies: 2
inputs: association football club
function: QueryAttr
dependencies: 3
inputs: official website
Answer: https://www.fcporto.pt/