Question: What operating system was developed by Sun Microsystems (the start time of this statement is 1983)?
Choices: macOS
Windows 7
Solaris
Linux
iOS
Android
FreeBSD
Brave
Windows XP
Mac OS
SPARQL: SELECT DISTINCT ?e WHERE { ?e <pred:instance_of> ?c . ?c <pred:name> "operating system" . ?e <developer> ?e_1 . ?e_1 <pred:name> "Sun Microsystems" .  [ <pred:fact_h> ?e ; <pred:fact_r> <developer> ; <pred:fact_t> ?e_1 ] <start_time> ?qpv . ?qpv <pred:year> 1983 .  }
Program:
function: Find
inputs: Sun Microsystems
function: Relate
dependencies: 0
inputs: developer
backward
function: QFilterYear
dependencies: 1
inputs: start time
1983
=
function: FilterConcept
dependencies: 2
inputs: operating system
function: What
dependencies: 3
Answer: Solaris