1. Copyright © 2002 Cycorp Introduction Fundamental Expression Types Top Level Collections Time and Dates Spatial Properties and Relations Event Types Information More Content Areas Survey of Knowledge Base Content

2. Copyright © 2002 Cycorp The Form and Content Of The Knowledge Base The main advantage of Cyc over other systems for representing knowledge is its use of a formal language in which inferential connections between concepts and statements are encoded in a machine accessible way. The content of the Knowledge Base comprises: –A vast taxonomy of concepts and relations –A rich formal representation of their interconnections

3. Arrangement, by Generality Facts (Database) Upper Ontology Core Theories Domain-Specific Theories Upper Ontology: Abstract Concepts Core Theories: Space, Time, Causality, … Domain-Specific Theories Facts: Instances Knowledge Base Layers

4. Arrangement, by Generality Facts (Database) Upper Ontology Core Theories Domain-Specific Theories EVENT  TEMPORAL-THING  INDIVIDUAL  THING Upper Ontology: Abstract Concepts Knowledge Base Layers

5. Arrangement, by Generality Facts (Database) Upper Ontology Core Theories Domain-Specific Theories EVENT  TEMPORAL-THING  INDIVIDUAL  THING For all events a and b, a causes b implies a precedes b Upper Ontology: Abstract Concepts Core Theories: Space, Time, Causality, … Knowledge Base Layers

6. Arrangement, by Generality Facts (Database) Upper Ontology Core Theories Domain-Specific Theories EVENT  TEMPORAL-THING  INDIVIDUAL  THING For all events a and b, a causes b implies a precedes b For any mammal m and any anthrax bacteria a, m’s being exposed to a causes m to be infected by a. Upper Ontology: Abstract Concepts Core Theories: Space, Time, Causality, … Domain-Specific Theories Knowledge Base Layers

7. Facts (Database) Upper Ontology Core Theories Domain-Specific Theories EVENT  TEMPORAL-THING  INDIVIDUAL  THING For all events a and b, a causes b implies a precedes b For any mammal m and any anthrax bacteria a, m’s being exposed to a causes m to be infected by a. John is a person infected by anthrax. Upper Ontology: Abstract Concepts Core Theories: Space, Time, Causality, … Domain-Specific Theories Facts: Instances Knowledge Base Layers Arrangement, by Generality

8. Copyright © 2002 Cycorp Summary The KB is a vast taxonomy of concepts and relations CycL is a rich formal representation of their interconnections The KB can be thought of as made up of layers ordered by degree of generality