/// <summary>Applies inference rules to assertions in the KnowledgeBase.</summary>
public virtual void Think()
{
// Implementation of this method has not been optimised for efficiency. Focus is on correctness for now
itsInferences = (TripleStore)itsAssertions.Clone();
itsInferences.Add(itsSchemas);
Rule axioms = MakeAxioms();
itsInferences.Evaluate(axioms);
int previousStatementCount = 0;
ArrayList rules = new ArrayList();
Rule rdf1 = new Rule();
rdf1.AddAntecedent(new Pattern(new Variable("uuu"), new Variable("aaa"), new Variable("yyy")));
rdf1.AddConsequent(new Pattern(new Variable("aaa"), Schema.rdf.type, Schema.rdf.Property));
rules.Add(rdf1);
Rule rdfs2 = new Rule();
rdfs2.AddAntecedent(new Pattern(new Variable("aaa"), Schema.rdfs.domain, new Variable("xxx")));
rdfs2.AddAntecedent(new Pattern(new Variable("uuu"), new Variable("aaa"), new Variable("yyy")));
rdfs2.AddConsequent(new Pattern(new Variable("uuu"), Schema.rdf.type, new Variable("xxx")));
rules.Add(rdfs2);
Rule rdfs3 = new Rule();
rdfs3.AddAntecedent(new Pattern(new Variable("aaa"), Schema.rdfs.range, new Variable("xxx")));
rdfs3.AddAntecedent(new Pattern(new Variable("uuu"), new Variable("aaa"), new Variable("vvv")));
rdfs3.AddConsequent(new Pattern(new Variable("vvv"), Schema.rdf.type, new Variable("xxx")));
rules.Add(rdfs3);
Rule rdfs4 = new Rule();
rdfs4.AddAntecedent(new Pattern(new Variable("uuu"), new Variable("aaa"), new Variable("xxx")));
rdfs4.AddConsequent(new Pattern(new Variable("uuu"), Schema.rdf.type, Schema.rdfs.Resource));
rdfs4.AddConsequent(new Pattern(new Variable("xxx"), Schema.rdf.type, Schema.rdfs.Resource));
rules.Add(rdfs4);
Rule rdfs5 = new Rule();
rdfs5.AddAntecedent(new Pattern(new Variable("uuu"), Schema.rdf.type, Schema.rdf.Property));
rdfs5.AddConsequent(new Pattern(new Variable("uuu"), Schema.rdfs.subPropertyOf, new Variable("uuu")));
rules.Add(rdfs5);
Rule rdfs6 = new Rule();
rdfs6.AddAntecedent(new Pattern(new Variable("uuu"), Schema.rdfs.subPropertyOf, new Variable("vvv")));
rdfs6.AddAntecedent(new Pattern(new Variable("vvv"), Schema.rdfs.subPropertyOf, new Variable("xxx")));
rdfs6.AddConsequent(new Pattern(new Variable("uuu"), Schema.rdfs.subPropertyOf, new Variable("xxx")));
rules.Add(rdfs6);
Rule rdfs7 = new Rule();
rdfs7.AddAntecedent(new Pattern(new Variable("aaa"), Schema.rdfs.subPropertyOf, new Variable("bbb")));
rdfs7.AddAntecedent(new Pattern(new Variable("uuu"), new Variable("aaa"), new Variable("yyy")));
rdfs7.AddConsequent(new Pattern(new Variable("uuu"), new Variable("bbb"), new Variable("yyy")));
rules.Add(rdfs7);
Rule rdfs8and10 = new Rule();
rdfs8and10.AddAntecedent(new Pattern(new Variable("uuu"), Schema.rdf.type, Schema.rdfs.Class));
rdfs8and10.AddConsequent(new Pattern(new Variable("uuu"), Schema.rdfs.subClassOf, Schema.rdfs.Resource));
rdfs8and10.AddConsequent(new Pattern(new Variable("uuu"), Schema.rdfs.subClassOf, new Variable("uuu")));
rules.Add(rdfs8and10);
Rule rdfs9 = new Rule();
rdfs9.AddAntecedent(new Pattern(new Variable("uuu"), Schema.rdfs.subClassOf, new Variable("xxx")));
rdfs9.AddAntecedent(new Pattern(new Variable("vvv"), Schema.rdf.type, new Variable("uuu")));
rdfs9.AddConsequent(new Pattern(new Variable("vvv"), Schema.rdf.type, new Variable("xxx")));
rules.Add(rdfs9);
Rule rdfs11 = new Rule();
rdfs11.AddAntecedent(new Pattern(new Variable("uuu"), Schema.rdfs.subClassOf, new Variable("vvv")));
rdfs11.AddAntecedent(new Pattern(new Variable("vvv"), Schema.rdfs.subClassOf, new Variable("xxx")));
rdfs11.AddConsequent(new Pattern(new Variable("uuu"), Schema.rdfs.subClassOf, new Variable("xxx")));
rules.Add(rdfs11);
Rule rdfs12 = new Rule();
rdfs12.AddAntecedent(new Pattern(new Variable("uuu"), Schema.rdf.type, Schema.rdfs.ContainerMembershipProperty));
rdfs12.AddConsequent(new Pattern(new Variable("uuu"), Schema.rdfs.subPropertyOf, Schema.rdfs.member));
rules.Add(rdfs12);
Rule rdfs13 = new Rule();
rdfs13.AddAntecedent(new Pattern(new Variable("uuu"), Schema.rdf.type, Schema.rdfs.Datatype));
rdfs13.AddConsequent(new Pattern(new Variable("uuu"), Schema.rdfs.subClassOf, Schema.rdfs.Literal));
rules.Add(rdfs13);
/*
* Can also add following OWL entailment rules
* (after Herman J. ter Horst, Extending the RDFS Entailment Lemma, Proceedings of 3rd International Semantic Web Conference)
*
* rdfp1: (?p rdf:type owl:FunctionalProperty) (?u ?p ?v) (?u ?p ?w) where v is URI or BlankNode then add (?v owl:sameAs ?w)
* rdfp2: (?p rdf:type owl:InverseFunctionalProperty) (?u ?p ?w) (?v ?p ?w) then add (?u owl:sameAs ?v)
* rdfp3: (?p rdf:type owl:SymmetricProperty) (?v ?p ?w) where w is URI or BlankNode then add (?w ?p ?v)
* rdfp4: (?p rdf:type owl:TransitiveProperty) (?u ?p ?v) (?v ?p ?w) then add (?u ?p ?w)
* rdfp5a: (?v ?p ?w) then add (?v owl:sameAs ?v)
* rdfp5b: (?v ?p ?w) where w is URI or BlankNode then add (?w owl:sameAs ?w)
* rdfp6: (?v owl:sameAs ?w) where w is URI or BlankNode then add (?w owl:sameAs ?v)
* rdfp7: (?u owl:sameAs ?v) (?v owl:sameAs ?w) then add (?u owl:sameAs ?w)
* rdfp8a: (?p owl:inverseOf ?q) (?v ?p ?w) where w is URI or BlankNode and q is URI then add (?w ?q ?v)
* rdfp8b: (?p owl:inverseOf ?q) (?v ?q ?w) where w is URI or BlankNode and q is URI then add (?w ?p ?v)
* rdfp9: (?v rdf:type rdfs:Class) (?v owl:sameAs ?w) then add (?v rdfs:subClassOf ?w)
* rdfp10: (?p rdf:type rdf:Property) (?p owl:sameAs ?q) then add (?p rdfs:subPropertyOf ?q)
*
*
*/
while (previousStatementCount != itsInferences.StatementCount)
{
previousStatementCount = itsInferences.StatementCount;
foreach (Rule rule in rules)
{
itsInferences.Evaluate(rule);
}
}
}