Question: What is the Twitter username of someone born in  Puerto Rico (Spanish as the official language there) ?
Choices:
_Brendonsmall
DrakeBell
hilaryswank
CP3
banantsfc
joeycrackts
damonalbarn
ThomasMannEP
lsu
POTUS
Answer: joeycrackts
SPARQL: SELECT DISTINCT ?pv WHERE { ?e <pred:instance_of> ?c . ?c <pred:name> "human" . ?e <place_of_birth> ?e_1 . ?e_1 <pred:name> "Puerto Rico" . ?e_1 <official_language> ?e_2 . ?e_2 <pred:name> "Spanish" .  ?e <Twitter_username> ?pv .  }
Program:
function: Find
inputs: Spanish
function: Relate
dependencies: 0
inputs: official language
backward
function: Find
inputs: Puerto Rico
function: And
dependencies: 1
2
function: Relate
dependencies: 3
inputs: place of birth
backward
function: FilterConcept
dependencies: 4
inputs: human
function: QueryAttr
dependencies: 5
inputs: Twitter username