Colloquium
Ontological Reasoning
for Natural Language Understanding
Fabian M. Suchanek
Supervisors: Prof. Dr-Ing. Gerhard Weikum
Dr. habil. Peter Baumgartner
Fabian M. Suchanek
Ontological Reasoning for Natural Language Understanding
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Overview
1.
Introduction to the Problem
2.
Our Approach
3.
1.
SUMO-Ontology
2.
Text Analysis
3.
KRHyper
Conclusions and Outlook
Fabian M. Suchanek
Ontological Reasoning for Natural Language Understanding
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Text Entailment
Hypothesis: „Elvis is still alive!“
Text:
...Yes, Elvis is alive...
...Elvis is not alive...
...Elvis is living incognito in a small Russian village...
...Elvis comes to Saarbrücken on January 1st...
Fabian M. Suchanek
Ontological Reasoning for Natural Language Understanding
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Plan of Attack
SUMOOntology
Text
subclass(funeral, socialinteraction).
subclass(literacyattribute, traitattribute).
subclass(mixedlanguage, spokenhumanlanguage).
subclass(pidginlanguage, spokenhumanlanguage).
subclass(creolelanguage, spokenhumanlanguage).
subclass(human,animal).
subclass(deafsignlanguage, manualhumanlanguage).).
subclass(radio, electricdevice).).
subclass(contractcarrier, transportationcompany).
subclass(commoncarrier, transportationcompany).
subclass(terminalbuilding, building).
subclass(trainstation, transitterminal).
subclass(representationalartwork, artwork).
subclass(artwork, artifact).
subclass(singlefamilyresidence, permanentresidence).
subclass(hotel, commercialagent).
subclass(hotel, temporaryresidence).
subclass(hotel, residentialbuilding).
subclass(residentialbuilding, residence).
subclass(residentialbuilding, building).
subclass(temporaryresidence, residence).
subclass(permanentresidence, residence).
subclass(residence, stationaryartifact).
subclass(room, stationaryartifact).
subclass(building, stationaryartifact).
comesTo(elvis,saarbruecken).
subclass(watercraft, vehicle).
subclass(train, railvehicle).
subclass(wagon, landvehicle).
subclass(railvehicle, landvehicle).
subclass(motorcycle, roadvehicle). subclass(artificialsatellite, satellite).
subclass(communicationdevice, engineeringcomponent).
subclass(contractcarrier, transportationcompany).
KRHyper-Rules
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Ontological Reasoning for Natural Language Understanding
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SUMO-Ontology – Concept Hierarchy
Entity
Abstract
ConstrictorSnake
Physical
Human
Anaconda
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Ontological Reasoning for Natural Language Understanding
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SUMO-Ontology – Axioms
instance(P, intentionalProcess) 
agent(P, A)
=> holdsDuring(when(P), attribute(A, awake))
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Ontological Reasoning for Natural Language Understanding
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SUMO-Ontology – Axioms
instance(P, intentionalProcess) 
agent(P, A)
=> holdsDuring(when(P), attribute(A, awake))
Functions
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Ontological Reasoning for Natural Language Understanding
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SUMO-Ontology – Axioms
instance(P, intentionalProcess) 
agent(P, A)
=> holdsDuring(when(P), attribute(A, awake))
Functions
Fabian M. Suchanek
Nested
Formulae
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O
SUMO-Ontology – Nested Formulae
thinks(bob, alive(elvis)  alive(priscilla) ).
alive(elvis)  alive(priscilla)
<=> alive(priscilla)  alive(elvis)
thinks(bob, alive(priscilla)  alive(elvis)).
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Ontological Reasoning for Natural Language Understanding
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SUMO-Ontology – Nested Formulae
thinks(bob, alive(elvis)  ¬alive(elvis) ).
alive(elvis)  ¬alive(elvis)
<=> false
<=> false  beautiful(priscilla)
thinks(bob, false  beautiful(priscilla)).
Fabian M. Suchanek
?
Ontological Reasoning for Natural Language Understanding
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O
Propositional Equivalence
says(bob,a)
says(bob,not(b))
a
b
p(t1,… q(t'1,…t'n'),… tn)
~~~~~>
x p(t1,…,x,… tn)  q(t'1,…t'n',x)
p(t1,… not(q(t'1,…t'n')),… tn)
~~~~~>
Fabian M. Suchanek
x p(t1,…,x,… tn)  q(t'1,…t'n',neg(x))
Ontological Reasoning for Natural Language Understanding
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Propositional Equivalence, Example
thinks(bob, alive(elvis)  ¬alive(elvis) )
=> thinks(bob, beautiful(priscilla) )
thinks(bob, wife(elvis,priscilla))
wife(X,Y) <=> husband(Y,X)
=> thinks(bob, husband(priscilla,elvis))
knows(bob, alive(elvis))
knows(X,Y) => believes(X,Y)
=> believes(bob, alive(elvis))
Fabian M. Suchanek
Ontological Reasoning for Natural Language Understanding
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Plan of Attack
SUMOOntology
Text
subclass(funeral, socialinteraction).
subclass(literacyattribute, traitattribute).
subclass(mixedlanguage, spokenhumanlanguage).
subclass(pidginlanguage, spokenhumanlanguage).
subclass(creolelanguage, spokenhumanlanguage).
subclass(human, animal).
subclass(deafsignlanguage, manualhumanlanguage).).
subclass(radio, electricdevice).).
subclass(contractcarrier, transportationcompany).
subclass(commoncarrier, transportationcompany).
subclass(terminalbuilding, building).
subclass(trainstation, transitterminal).
subclass(representationalartwork, artwork).
subclass(artwork, artifact).
subclass(singlefamilyresidence, permanentresidence).
subclass(hotel, commercialagent).
subclass(hotel, temporaryresidence).
subclass(hotel, residentialbuilding).
subclass(residentialbuilding, residence).
subclass(residentialbuilding, building).
subclass(temporaryresidence, residence).
subclass(permanentresidence, residence).
subclass(residence, stationaryartifact).
subclass(room, stationaryartifact).
subclass(building, stationaryartifact).
comesTo(elvis, Saarbruecken).
subclass(watercraft, vehicle).
subclass(train, railvehicle).
subclass(wagon, landvehicle).
subclass(railvehicle, landvehicle).
subclass(motorcycle, roadvehicle). subclass(artificialsatellite, satellite).
subclass(communicationdevice, engineeringcomponent).
subclass(contractcarrier, transportationcompany).
KRHyper-Rules
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Ontological Reasoning for Natural Language Understanding
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Text Analysis
S
VP
Comp
Noun Verb Prep
Elvis comes
Fabian M. Suchanek
to
Noun
Saarbrücken
Ontological Reasoning for Natural Language Understanding
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O
Mapping a Sentence to SUMO
?
Elvis comes to Saarbrücken
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Ontological Reasoning for Natural Language Understanding
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Mapping a Sentence to SUMO
BodyMotion
Elvis comes to Saarbrücken
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Ontological Reasoning for Natural Language Understanding
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Mapping a Sentence to SUMO
BodyMotion
Agent
Destination
?
?
Elvis comes to Saarbrücken
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Ontological Reasoning for Natural Language Understanding
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O
Mapping a Sentence to SUMO
BodyMotion
Agent
Destination
Elvis comes to Saarbrücken
instance(b,bodymotion).
agent(b,elvis).
destination(b,saarbruecken).
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Ontological Reasoning for Natural Language Understanding
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Plan of Attack
SUMOOntology
Text
subclass(funeral, socialinteraction).
subclass(literacyattribute, traitattribute).
subclass(mixedlanguage, spokenhumanlanguage).
subclass(pidginlanguage, spokenhumanlanguage).
subclass(creolelanguage, spokenhumanlanguage).
subclass(human, animal).
subclass(deafsignlanguage, manualhumanlanguage).).
subclass(radio, electricdevice).).
subclass(contractcarrier, transportationcompany).
subclass(commoncarrier, transportationcompany).
subclass(terminalbuilding, building).
subclass(trainstation, transitterminal).
subclass(representationalartwork, artwork).
subclass(artwork, artifact).
subclass(singlefamilyresidence, permanentresidence).
subclass(hotel, commercialagent).
subclass(hotel, temporaryresidence).
subclass(hotel, residentialbuilding).
subclass(residentialbuilding, residence).
subclass(residentialbuilding, building).
subclass(temporaryresidence, residence).
subclass(permanentresidence, residence).
subclass(residence, stationaryartifact).
subclass(room, stationaryartifact).
subclass(building, stationaryartifact).
comesTo(elvis, Saarbruecken).
subclass(watercraft, vehicle).
subclass(train, railvehicle).
subclass(wagon, landvehicle).
subclass(railvehicle, landvehicle).
subclass(motorcycle, roadvehicle). subclass(artificialsatellite, satellite).
subclass(communicationdevice, engineeringcomponent).
subclass(contractcarrier, transportationcompany).
KRHyper-Rules
Fabian M. Suchanek
Ontological Reasoning for Natural Language Understanding
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KRHyper
‫ ر‬First-Order-Reasoning System
‫ ر‬Developed at the University of Koblenz/Germany
by P. Baumgartner and C. Wernhard
‫ ر‬Given some facts and rules, calculates a set of
entailed facts
entailed
Facts+
Rules
Fabian M. Suchanek
Ontological Reasoning for Natural Language Understanding
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O
Application
SUMOOntology
attribute(A, alive) ← agent(P,A)
 instance(P,process).
subclass(bodyMotion, process).
Text
Hypothesis
instance(b,bodyMotion).
agent(b,elvis).
false ← attribute(elvis,alive).
instance(b,process).
attribute(elvis,alive).
Fabian M. Suchanek
Ontological Reasoning for Natural Language Understanding
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Results
‫ ر‬It is possible to enhance question answering
by a kind of common sense reasoning
‫ ر‬There is still a long way to go to practical applicability
Fabian M. Suchanek
Ontological Reasoning for Natural Language Understanding
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O
Outlook
Idea: Learn the Ontology from the Web
Web
(Wikipedia)
Fabian M. Suchanek
Free Text
+ HTML
+ Ontological
Knowledge
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Conclusion
Elvis is alive,
but there‘s still much work to do.
References:
KRHyper:
http://www.uni-koblenz.de/~wernhard/krhyper
SUMO:
http://www.ontologyportal.org
Comp. Linguistics:
http://www.coli.uni-saarland.de
Thesis:
http://www.mpii.mpg.de/~suchanek/personal
Fabian M. Suchanek
Ontological Reasoning for Natural Language Understanding
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