File: KEHOME/doc/simplifylattice.html Subject: Create and Simplify an Ontology Lattice From: Richard H. McCullough Date: May 11, 2003 Contents 1. Create an ontology lattice 2. Simplify an ontology lattice 3. RDF Ontology lattice 4. OWL Ontology lattice The results in sections 3 and 4 were generated by MKE using the MKR scripts KEHOME/knowledge/applications/SemanticWeb/RDF/lattice.mkr KEHOME/knowledge/applications/SemanticWeb/OWL/lattice.mkr KEHOME=http://rhm.cdepot.net 1. Create an ontology lattice Use the ontology RDF file. Note: includes mkr:Entity from KEHOME/kb/tabrasa.html 1.1. Replace rdfs:Class with rdfs:Resource 1.2. Replace rdfs:Resource with owl:Thing To avoid infinite loops, delete statements of the form owl:Thing rdf:type x owl:Thing rdfs:subClassOf x owl:Thing rdfs:subPropertyOf x 1.3. Delete any statements involving owl:Nothing owl:Nothing is the class of things that do not exist. It is not part of the ontology lattice. 1.4. For every statement of the form x rdf:type y enter x isu y (x is an individual of y) For every statement of the form x rdfs:subClassOf y enter x iss y (x is a species of y) For every statement of the form x rdfs:subPropertyOf y enter x isu y (x is an individual of y) 1.5. For every statement of the form x isu y enter x isa y For every statement of the form x iss y enter x isa y 1.6. Use isa links to create ontology lattice. 2. Simplify an ontology lattice See simplify_lattice() in KEHOME/src/integrate.icn See check_uslink() in KEHOME/src/check.icn See check_genus() in KEHOME/src/check.icn 2.1. For every x with x isu y x iss z change to x iss y x iss z In other words, x is a class, not an individual. 2.2. For every x with x isa y x isa z g := least upper bound(y,z) g is y or z delete x isa g x isu g (if present) x iss g (if present) In other words, keep only the most specific links. 3. RDF Ontology lattice 3.1. RDF file from Appendix A: RDF Schema as RDF/XML RDF Vocabulary Description Language 1.0: RDF Schema W3C Working Draft 23 January 2003 KEHOME/knowledge/applications/SemanticWeb/RDF/rdfVDLA.rdf 3.2. RDF Ontology lattice KEHOME/knowledge/applications/SemanticWeb/RDF/lattice.save 4. OWL Ontology lattice 4.1. RDF file from Appendix B: RDF Schema of OWL OWL Web Ontology Language Reference W3C Working Draft 31 March 2003 KEHOME/knowledge/applications/SemanticWeb/OWL/owlRefB.rdf 4.2. OWL Ontology lattice KEHOME/knowledge/applications/SemanticWeb/OWL/lattice.save