[seek-kr-sms] OWL Inference APIs (was Re: SMS stuff)

[Bertram Ludaescher]

Serguei:

Good points! I agree that it would be useful to understand what
features are needed most in SEEK -- I guess the answer is "it
depends".

I would hope that for many things (e.g., the core SMS, semantic typing 
etc) we can get away with "standard" reasoning approaches, w/o getting 
all the way to the very fancy features that are at the bleeding CS
edge. While those are very exciting, I fear they will make us sweat a
lot. Even reasoners for "standard" DLs have problems it seems...

but maybe we should just bite the bullet and run with those fancy
examples you have.

Do you have plans to use existing or tweak, extend existing reasoners?
(we have some plans here on that too ...)

Bertram

>>>>> "SK" == Serguei Krivov <Serguei.Krivov at uvm.edu> writes:
SK> 
SK> Shawn,
SK> Thanks for the interesting survey. I also have been looking at DL
SK> reasoning with focus on tableaux algorithms and found a few points worth
SK> of attention. Apparently there are a few semantic features which are not
SK> part of present owl, but they are extremely useful and they are
SK> available in some decidable systems.
SK> 1. Role boxes: In owl one can not say that role Uncle is subrole of
SK> composition of roles Parent*Brother. Role boxes were avoided for a long
SK> time since in general they lead to undecidable systems. But apparently
SK> some limited (acyclic) role boxes can be added to SHIQ without loose of
SK> decidability:
SK> http://www.cs.man.ac.uk/~horrocks/Publications/download/2003/HoSa03a.pdf
SK> 
SK> 2. Feature(functional role) agreement. In owl one can not say something
SK> like
SK> "for every chemical flow its agent should be the same as agent of
SK> respective stocks it connect"-
SK> flow.agent=flow.source.agent=flow.target.agent. But in very old system
SK> ALCF it is possible. Apparently addition of  agreement/disagreement for
SK> functional roles does not lead to undesirability in many even more
SK> complex cases.
SK> 
SK> 3. Reasoning with concrete domain vs time and space. Reasoning about
SK> space and time may not be important for general users of ontologies so
SK> it is not in owl. But it is important for ecologists and perhaps
SK> eventually we shall bump in it. Although Racer supports reasoning with
SK> concrete domains such as integers and friends, it does not come to
SK> space/time. Yet potentially we can use DL reasoner for checking
SK> consistency of statements about space, time , and even space-time as
SK> long as they are represented properly (as admissible domain). I am
SK> attaching paper that surveys this topic in detail. Specifically
SK> interesting points about space and time are in the end and of course
SK> there are many references on this subject worth of reading. 
SK> 
SK> Certainly it is not possible to combine all semantic features we need in
SK> one decidable DL system.   But I think it would be good to understand
SK> what features are the most important in context of SEEK. Then we can try
SK> to design a tableaux that accommodates most of the essential features we
SK> need.  
SK> 
SK> Serguei