Question: Which has the largest discharge among the rivers that are a tributary of the North Sea?
Choices: Danube
Ohio River
Mississippi River
Columbia River
Rhine
Hudson River
Amazon
Missouri River
Richard Hunt
River Thames
SPARQL: SELECT ?e WHERE { ?e <pred:instance_of> ?c . ?c <pred:name> "river" . ?e_1 <tributary> ?e . ?e_1 <pred:name> "North Sea" .  ?e <discharge> ?pv . ?pv <pred:value> ?v .  } ORDER BY DESC(?v) LIMIT 1
Program:
function: Find
inputs: North Sea
function: Relate
dependencies: 0
inputs: tributary
forward
function: FilterConcept
dependencies: 1
inputs: river
function: SelectAmong
dependencies: 2
inputs: discharge
largest
Answer: Rhine