Opisna logika (engl.Description logics, DL) je porodica jezika za formalno predstavljanje znanja. Mnoge opisne logike su ekspresivnije od propozicione logike, ali manje ekspresivne od logike prvog reda. Za razliku od potonje, sržni problemi rasuđivanja za opisnu logiku su (obično) rešivi, a efikasne procedure odlučivanja su dizajnirane i primenjene za ove probleme. Postoje opšta, prostorna, vremenska, prostorno vremenska i rasplinuta opisna logika, i svaka opisna logika karakteriše drugačiji balans između izražajne moći i složenostirasuđivanja podržavajući različite skupove matematičkih konstruktora.[1]
Opisna logika se koristi u veštačkoj inteligenciji za opisivanje i obrazloženje relevantnih koncepata domena aplikacije (poznatog kao terminološko znanje). To je od posebnog značaja u obezbeđivanju logičkog formalizma za ontologije i semantičku mrežu: veb ontološki jezik (OWL) i njegovi profili su zasnovani na opisnoj logici. Najznačajnija primena opisne logike i OWL je u biomedicinskoj informatici gde opisna logika pomaže u kodifikaciji biomedicinskog znanja.
Uvod
Opisna logika modeluje koncepte, uloge i pojedince i njihove odnose.
Osnovni koncept ovog vida modelovanja je aksiom — logički iskaz koji se odnosi na uloge i/ili koncepte.[2] Ovo je ključna razlika od paradigme okvira gde specifikacija okvira deklariše i potpuno definiše klasu.[2]
F. Baader, D. Calvanese, D. L. McGuinness, D. Nardi, P. F. Patel-Schneider (2003). The Description Logic Handbook: Theory, Implementation, Applications. Cambridge, UK: Cambridge University Press. ISBN0-521-78176-0.CS1 одржавање: Вишеструка имена: списак аутора (веза)
D. Fensel, F. van Harmelen, I. Horrocks, D. McGuinness, and P. F. Patel-Schneider (2001). „OIL: An Ontology Infrastructure for the Semantic Web”(PDF). IEEE Intelligent Systems. 16 (2): 38—45.CS1 одржавање: Вишеструка имена: списак аутора (веза), .
Ian Horrocks and Peter F. Patel-Schneider: The Generation of DAML+OIL. In Proceedings of the 2001 Description Logic Workshop (DL 2001), volume 49 of CEUR <http://ceur-ws.org/>, pages 30–35, 2001.
Bernardo Cuenca Grau, Ian Horrocks, Boris Motik, Bijan Parsia, Peter Patel-Schneider, and Ulrike Sattler (новембар 2008). „OWL 2: The next step for OWL”(PDF). Journal of Web Semantics. 6 (4): 309—322.CS1 одржавање: Вишеструка имена: списак аутора (веза)CS1 одржавање: Формат датума (веза),.
Franz Baader, Ian Horrocks, and Ulrike Sattler: Chapter 3 Description Logics. In Frank van Harmelen, Vladimir Lifschitz, and Bruce Porter, editors, Handbook of Knowledge Representation. Elsevier, 2007.
Alessandro Artale and Enrico Franconi: Temporal Description Logics. In Handbook of Temporal Reasoning in Artificial Intelligence, 2005.
Jens Lehmann: DL-Learner: Learning concepts in description logics, Journal of Machine Learning Research, 2009.
Franz Baader: Description Logics. In Reasoning Web: Semantic Technologies for Information Systems, 5th International Summer School, volume 5689 of Lecture Notes in Computer Science, pages 1–39. Springer, 2009. (springerlink) Introductory text with a focus on reasoning and language design, and an extended historical overview.
Enrico Franconi: Introduction to Description Logics. Course materials. Faculty of Computer Science, Free University of Bolzano, Italy, 2002. Lecture slides and many literature pointers, somewhat dated.
Ian Horrocks. „Ontologies and the Semantic Web”(PDF). Communications of the ACM. 51 (12): 58—67. децембар 2008.CS1 одржавање: Формат датума (веза),. A general overview of knowledge representation in Semantic Web technologies.
KAON2 is a free (for non-commercial use) Java-based reasoner, offering fast reasoning support for OWL ontologies.
MSPASS is a free open-source C reasoner for numerous DL models.
Pellet is a dual-licensed (AGPL and proprietary) commercial, Java-based reasoner.
RacerPro of Racer Systems was a commercial (free trials and research licenses are available) lisp-based reasoner, today both an open source version of RACER exists from the original developers at Lübeck University using the BSD 3 license, and also a commercialized version, still named RacerPro by Franz Inc.
Sim-DL is a free open-source Java-based reasoner for the language ALCHQ. It also provides a similarity measurement functionality between concepts. To access this functionality a Protégé plugin can be used.
Owlready2 is a package for ontology-oriented programming in Python. It can load OWL 2.0 ontologies as Python objects, modify them, save them, and perform reasoning via HermiT (included). Owlready2 allows a transparent access to OWL ontologies (contrary to usual Java-based API).
Editori
Protégé is a free, open-source ontology editor and a knowledge base framework, which can use DL reasoners offering DIG Interface as a back end for consistency checks.