Question: When did  John Powell (the one whose date of death is 2017-12-25) become a member of Boston United F.C.?
Choices: 1923-01-01
1754-01-01
1896-01-04
1986-09-13
1996-03-11
1974-06-18
1969-01-20
1872-01-01
1969-01-01
1981-09-15
SPARQL: SELECT DISTINCT ?qpv WHERE { ?e_1 <pred:name> "John Powell" . ?e_1 <date_of_death> ?pv . ?pv <pred:date> "2017-12-25"^^xsd:date . ?e_2 <pred:name> "Boston United F.C." . ?e_1 <member_of_sports_team> ?e_2 . [ <pred:fact_h> ?e_1 ; <pred:fact_r> <member_of_sports_team> ; <pred:fact_t> ?e_2 ] <start_time> ?qpv .  }
Program:
function: Find
inputs: John Powell
function: FilterDate
dependencies: 0
inputs: date of death
2017-12-25
=
function: Find
inputs: Boston United F.C.
function: QueryRelationQualifier
dependencies: 1
2
inputs: member of sports team
start time
Answer: 1969-01-01