Question: Which town is, since 1st January 1956, the twinned administrative body of a big city whose local dialing code is 06131 ?
Choices: Colchester
South Shields
Wigan
Blackburn
Watford
Wimbledon
Royal Tunbridge Wells
Macclesfield
Basingstoke
Edmonton
SPARQL: SELECT DISTINCT ?e WHERE { ?e <pred:instance_of> ?c . ?c <pred:name> "town" . ?e <twinned_administrative_body> ?e_1 . ?e_1 <pred:instance_of> ?c_1 . ?c_1 <pred:name> "big city" . ?e_1 <local_dialing_code> ?pv . ?pv <pred:value> "06131" .  [ <pred:fact_h> ?e ; <pred:fact_r> <twinned_administrative_body> ; <pred:fact_t> ?e_1 ] <start_time> ?qpv . ?qpv <pred:date> "1956-01-01"^^xsd:date .  }
Program:
function: FindAll
function: FilterStr
dependencies: 0
inputs: local dialing code
06131
function: FilterConcept
dependencies: 1
inputs: big city
function: Relate
dependencies: 2
inputs: twinned administrative body
backward
function: QFilterDate
dependencies: 3
inputs: start time
1956-01-01
=
function: FilterConcept
dependencies: 4
inputs: town
function: What
dependencies: 5
Answer: Watford