OWL Lite o An even further restriction limits owl dl to a subset of the language constructors E.g., OWL Lite excludes enumerated classes disjointness statements, and arbitrary cardinality o The advantage of this is a language that is easier to grasp, for users implement, for tool builders o The disadvantage is restricted expressivity 16 Chapter 4 A Semantic Web primer
Chapter 4 A Semantic Web Primer 16 OWL Lite ⚫ An even further restriction limits OWL DL to a subset of the language constructors – E.g., OWL Lite excludes enumerated classes, disjointness statements, and arbitrary cardinality. ⚫ The advantage of this is a language that is easier to – grasp, for users – implement, for tool builders ⚫ The disadvantage is restricted expressivity
Upward Compatibility between OWL Species o Every legal oWL Lite ontology is a legal OWL DL ontology Every legal oWL DL ontology is a legal OWL Full ontology o Every valid OWL Lite conclusion is a valid OWL DL conclusion o Every valid OWL DL conclusion is a valid OWL Full conclusion 17 Chapter 4 A Semantic Web primer
Chapter 4 A Semantic Web Primer 17 Upward Compatibility between OWL Species ⚫ Every legal OWL Lite ontology is a legal OWL DL ontology ⚫ Every legal OWL DL ontology is a legal OWL Full ontology ⚫ Every valid OWL Lite conclusion is a valid OWL DL conclusion ⚫ Every valid OWL DL conclusion is a valid OWL Full conclusion
OWL Compatibility with RDF Schema e All varieties of oWL use RDF for their syntax rdfs Resource Instances are declared as in RDf, using RDF descriptions rdfs Class rdf: Property and typing information OWL constructors are specialisations of their owt: Class owl: Object Property owl: DatatypeProperty RDF counterparts 18 Chapter 4 A Semantic Web primer
Chapter 4 A Semantic Web Primer 18 OWL Compatibility with RDF Schema ⚫ All varieties of OWL use RDF for their syntax ⚫ Instances are declared as in RDF, using RDF descriptions ⚫ and typing information OWL constructors are specialisations of their RDF counterparts
OWL Compatibility with RDF Schema(2) e Semantic Web design aims at downward compatibility with corresponding reuse of software across the various layers o The advantage of full downward compatibility for OWL is only achieved for OWL Full, at the cost of computational intractability 19 Chapter 4 A Semantic Web primer
Chapter 4 A Semantic Web Primer 19 OWL Compatibility with RDF Schema (2) ⚫ Semantic Web design aims at downward compatibility with corresponding reuse of software across the various layers ⚫ The advantage of full downward compatibility for OWL is only achieved for OWL Full, at the cost of computational intractability
Lecture Outline Basic ldeas of owl 2. The OWL Language 3. Examples 4. The oWL Namespace 5. Future Extensions 20 Chapter 4 A Semantic Web primer
Chapter 4 A Semantic Web Primer 20 Lecture Outline 1. Basic Ideas of OWL 2. The OWL Language 3. Examples 4. The OWL Namespace 5. Future Extensions