Question: When did Shanghai (the one whose local dialing code is 21) become the twinned administrative body of Porto (the one whose official name is Porto)?
Choices: 1995-01-01
2009-12-06
1953
1793-01-01
2006-10-11
1990-03-18
2010-05-27
1881-01-01
2011-09-27
1946-07-04
SPARQL: SELECT DISTINCT ?qpv WHERE { ?e_1 <pred:name> "Shanghai" . ?e_1 <local_dialing_code> ?pv . ?pv <pred:value> "21" . ?e_2 <pred:name> "Porto" . ?e_2 <official_name> ?pv_1 . ?pv_1 <pred:value> "Porto" . ?e_1 <twinned_administrative_body> ?e_2 . [ <pred:fact_h> ?e_1 ; <pred:fact_r> <twinned_administrative_body> ; <pred:fact_t> ?e_2 ] <start_time> ?qpv .  }
Program:
function: Find
inputs: Shanghai
function: FilterStr
dependencies: 0
inputs: local dialing code
21
function: Find
inputs: Porto
function: FilterStr
dependencies: 2
inputs: official name
Porto
function: QueryRelationQualifier
dependencies: 1
3
inputs: twinned administrative body
start time
Answer: 1995-01-01