Question: Which class of instruments has Arjen Anthony Lucassen and Richard Wright (who plays the synthesizer instrument) in its famous people?
Choices: goblet drum
didgeridoo
xylophone
accordion
bass guitar
progressive rock
trombone
mellotron
Timbales
psychedelic rock
SPARQL: SELECT DISTINCT ?e WHERE { ?e <pred:instance_of> ?c . ?c <pred:name> "class of instruments" . ?e <famous_people> ?e_1 . ?e_1 <pred:name> "Arjen Anthony Lucassen" .  ?e <famous_people> ?e_2 . ?e_2 <pred:name> "Richard Wright" . ?e_2 <instrument> ?e_3 . ?e_3 <pred:name> "synthesizer" .  }
Program:
function: Find
inputs: Arjen Anthony Lucassen
function: Relate
dependencies: 0
inputs: famous people
backward
function: FilterConcept
dependencies: 1
inputs: class of instruments
function: Find
inputs: synthesizer
function: Relate
dependencies: 3
inputs: instrument
backward
function: Find
inputs: Richard Wright
function: And
dependencies: 4
5
function: Relate
dependencies: 6
inputs: famous people
backward
function: FilterConcept
dependencies: 7
inputs: class of instruments
function: And
dependencies: 2
8
function: What
dependencies: 9
Answer: mellotron