Tools for

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• Tools for
• DAML-Based Services,
• Query Answering, and
• Ontology Development

Richard Fikes Deborah McGuinness Sheila
McIlraith Gleb Frank Jessica Jenkins
Yulin Li Son Tran Honglei Zee
Knowledge Systems Laboratory Stanford
University www.ksl.stanford.edu
7/19/01

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Project Overview

• Hot DAML-enabled Web services
• Hot Reasoning with knowledge represented in DAML

• DAML language development
• Member of joint markup language committee
• Proposed co-chair of W3C WebOnt committee
• Developed and maintain axiomatic semantics
• Ontology development environments
• Chimaera ontology diagnosis tool
• Translators to enable interoperation with OKBC
  tools

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Reasoning With DAML Knowledge Bases

• JTP a DAMLOIL reasoner
• Richard Fikes, Gleb Frank, Yulin Li
• Hybrid reasoning architecture
• FOL model elimination theorem prover
• Suite of special purpose reasoners
• Special purpose DAMLOIL reasoner
• Efficient storage of RDF statements (triples)
• Linking of property value sets
• Based on the axiomatic semantics
• Implemented in JAVA

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Forward Chaining Infers RDF Statements

• Assumed assertions
• (PropertyValue subClassOf Restriction Class)
• (PropertyValue subClassOf Class rdfsClass)
• (Type subClassOf TransitiveProperty)
• (PropertyValue disjointWith Property rdfsClass)
• Forward chaining rules
• (gt (and (Type ?p TransitiveProperty)
• (PropertyValue ?p ?x ?y)
• (PropertyValue ?p ?y ?z))
• (PropertyValue ?p ?x ?z))
• (gt (and (PropertyValue disjointWith ?cl ?super)
• (PropertyValue subClassOf ?sub ?super))
• (PropertyValue disjointWith ?cl ?sub))
• Inferred assertions
• (PropertyValue subClassOf Restriction rdfsClass)
  
• (PropertyValue disjointWith Property Restriction)

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Forward Chaining Infers Inconsistencies

• Incorrect portion of translated Wines KB
• (Type color Property)
• (PropertyValue maxCardinality color 1)
• Assumed assertion
• (PropertyValue domain maxCardinality Restriction)
• Forward chaining rules
• (gt (and (PropertyValue domain ?prop ?dm)
• (PropertyValue ?prop ?fr ?val))
• (Type ?fr ?dm))
• (gt (and (PropertyValue disjointWith ?c1 ?c2)
• (Type ?i ?c1)
• (Type ?i ?c2))
• false)
• Inferences
• (Type color Restriction)
• (PropertyValue disjointWith Property Restriction)
  
• false ?

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Current Challenges for JTP

• Decrease time for loading knowledge bases
• Add functionality to backward chainer
• DAML query language
• DAML rationale language
• for explaining query answers
• ?More at Friday mornings breakout session on
  reasoning?