Implemented Description Logic-based Systems

Some implemented systems are listed here:

• BACK - A description logic implemented in PROLOG from the Technical University of Berlin.

• CLASSIC - A description logic from AT&T Laboratories implemented first in Lisp and later in C and C++. It has aimed to balance expressive power and computational complexity and is one of the less expressive implemented systems. It is the basis of a number of configuration and data mining applications, notibly PROSE from AT&T and Lucent and the Management Discovery Tool from NCR. CLASSIC has “(severely) constraining expressiveness so that (Tbox) reasoning can be performed in polynomial time “

• CRACK - A highly expressive description logic from IRST. It is the basis of over 100 natural language applications.

• FLEX - A description logic from the Technical University of Berlin. It is the basis of a very large natural language application.

• K-REP - A description logic from IBM. It is the basis of a large medical application.

• KL-ONE - The original description logic-based system (earlier called structured inheritance networks or terminological logics).

• KRIS - An expressive description logic originally from DFKI (the German Institute for Artificial Intelligence). KRIS “uses sound and complete reasoning algorithms for logics with high worst case complexities (on the grounds that the pathological cases which give rise to the theoretical complexity results are unlikely to arise in practice)”

• LOOM - A highly expressive description logic-based system from University of California - Information Sciences Institute. It is the basis of many applications funded by ARPA. LOOM has “tractable but incomplete reasoning algorithms”

• YAK - A description logic-based system which was a predecessor to CRACK also from IRST in Italy.

Another list of description logic systems is reachable from the description logic home page .

Sowa: "The database marketplace has been using FOL and Horn clauses for the past  30 years.......The DL thought police immediately excommunicate anyone who mentions Horn clauses or FOL. (Just ask Bob MacGregor.)"