1. 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
7/19/01

2. Knowledge Systems Laboratory, Stanford University
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
Knowledge Systems Laboratory, Stanford University

3. Reasoning With DAML Knowledge Bases
JTP – a DAML+OIL reasoner
Richard Fikes, Gleb Frank, Yulin Li
Hybrid reasoning architecture
FOL model elimination theorem prover
Suite of special purpose reasoners
Special purpose DAML+OIL reasoner
Efficient storage of RDF statements (triples)
Linking of property value sets
Based on the axiomatic semantics
Implemented in JAVA
Knowledge Systems Laboratory, Stanford University

4. Forward Chaining Infers RDF Statements
Assumed assertions
(PropertyValue subClassOf Restriction Class)
(PropertyValue subClassOf Class rdfs:Class)
(Type subClassOf TransitiveProperty)
(PropertyValue disjointWith Property rdfs:Class)
Forward chaining rules
(=> (and (Type ?p TransitiveProperty)
(PropertyValue ?p ?x ?y)
(PropertyValue ?p ?y ?z))
(PropertyValue ?p ?x ?z))
(=> (and (PropertyValue disjointWith ?cl ?super)
(PropertyValue subClassOf ?sub ?super))
(PropertyValue disjointWith ?cl ?sub))
Inferred assertions
(PropertyValue subClassOf Restriction rdfs:Class)
(PropertyValue disjointWith Property Restriction)
Knowledge Systems Laboratory, Stanford University

5. 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
(=> (and (PropertyValue domain ?prop ?dm)
(PropertyValue ?prop ?fr ?val))
(Type ?fr ?dm))
(=> (and (PropertyValue disjointWith ?c1 ?c2)
(Type ?i ?c1)
(Type ?i ?c2))
false)
Inferences
(Type color Restriction)
(PropertyValue disjointWith Property Restriction)
false 
Knowledge Systems Laboratory, Stanford University

6. 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 morning’s breakout session on reasoning
Knowledge Systems Laboratory, Stanford University