Home

About

Advanced Search

Browse by Discipline

Scientific Societies

E-print Alerts

Add E-prints

E-print Network
FAQHELPSITE MAPCONTACT US


  Advanced Search  

 
G53KRR handout on description logic. Variety of description logics/ontology languages. This lecture (based on Brachman and
 

Summary: G53KRR handout on description logic.
Variety of description logics/ontology languages. This lecture (based on Brachman and
Levesque chapter 9) is only one particular flavour of description logic. There are very many, with
different syntax and expressive power.
Basic idea description logic talks about relationships between concepts (noun phrases).
Precise definition of the syntax of DL :
Logical symbols (apart from brackets etc.):
concept-forming operators: ALL, EXISTS, FILLS, AND
connectives: ,
.
=,
symbols for numbers (1,2,3,...),
Non-logical symbols:
Atomic concepts: Person, Thing,. . . . Correspond to unary predicates in FOL.
Roles: :Age, :Employer, :Child, :Arm, . . .. Correspond to binary predicates in FOL.
Constants: john, mary, roomA7, . . .. Correspond to constants (0-ary functional symbols) in
FOL.
Concepts:
atomic concept is a concept
if r is a role and b is a concept, then [ALL r b] is a concept (e.g. [ALL : Child Girl]

  

Source: Alechina, Natasha - School of Computer Science, University of Nottingham

 

Collections: Computer Technologies and Information Sciences