- From: Chris Mungall <cjm@berkeleybop.org>
- Date: Thu, 29 Apr 2010 15:00:02 -0700
- To: Alan Rector <rector@cs.man.ac.uk>
- Cc: Owl Dev <public-owl-dev@w3.org>, sonic@tcs.inf.tu-dresden.de
On Apr 29, 2010, at 4:08 AM, Alan Rector wrote: > Chris > > Can you define your use case a bit more clearly? I'm after an implementation of a function: lcs(C,D) -> A where C, D and A are either named classes or class expressions, and A subsumes both C and D, and there is no A' such that A'\=A and A subsumes both C and D, against some background TBox employing some subset of OWL2 constructs and axioms (e.g. EL) or some approximation thereof (open to heuristic approaches) > Are you trying to find the simplest expression for a defined class > that would be guaranteed to subsume both C and D (excluding simply C > or D)? > If so is the interest in finding the subsumer or in the structure of > the expressions in the definition > > Are you intrested only in named classes? > > e.g. C=B & r some Q > D=B & r some S > > A = B & r some (Q or S) > > or do you care about the named subsumers of Q and S. > > (I won't have a solution, but I am curious as to what the problem is?) > > Or there's the least common named subsumer in the inferred > classification lattice > using lattice theoretical tools, but I presume that is not what you > are asking or > you wouldn't be asking it. Correct, it would be a solved problem if the result was drawn only from the set of named classes. > Regards > > Alan > > On 28 Apr 2010, at 04:18, Chris Mungall wrote: > >> I'm looking for efficient implementations of the LCS (least common >> subsumer) function for OWL. The function take two classes or class >> expressions C, D and return the minimal class or class expression >> that subsumes both. Obviously this excludes UnionOf constructs used >> in the results. Intersection and existential restrictions would be >> fine. >> >> I see there's a vast literature on this going back to the earliest >> days of DL systems, but surprisingly little in the way of >> implementations. >> >> The only implementation I'm aware of is SONIC: >> >> http://wwwtcs.inf.tu-dresden.de/~sonic/ >> >> But this has two drawbacks from my perspective: >> >> * It's not open source, and requires non-open source tools >> * It looks like it's not maintained (the installation instructions >> say that OilEd is required) >> >> Ideally the implementation would be open source and well-integrated >> with current tools (e.g. works with the OWLAPI and/or OWLlink). I'd >> be willing to work a little on the plumbing, but not for closed >> source tools. >> >> >> > > ----------------------- > Alan Rector > Professor of Medical Informatics > School of Computer Science > University of Manchester > Manchester M13 9PL, UK > TEL +44 (0) 161 275 6149/6188 > FAX +44 (0) 161 275 6204 > www.cs.man.ac.uk/~rector > www.co-ode.org > http://clahrc-gm.nihr.ac.uk/ > > > > > > >
Received on Thursday, 29 April 2010 22:00:37 UTC