Question: Regarding the organization that has airline callsign is CLIPPER, when is the work period (end)
Choices: 1991
1950
2001
1977
2009
2006
1962
2019
2016
2013
SPARQL: SELECT DISTINCT ?pv WHERE { ?e <pred:instance_of> ?c . ?c <pred:name> "organization" . ?e <callsign_of_airline> ?pv_1 . ?pv_1 <pred:value> "CLIPPER" . ?e <work_period_(end)> ?pv .  }
Program:
function: FindAll
function: FilterStr
dependencies: 0
inputs: callsign of airline
CLIPPER
function: FilterConcept
dependencies: 1
inputs: organization
function: QueryAttr
dependencies: 2
inputs: work period (end)
Answer: 1991