- From: Pat Hayes <phayes@ihmc.us>
- Date: Mon, 5 Mar 2007 14:52:31 -0600
- To: Bijan Parsia <bparsia@cs.man.ac.uk>
- Cc: "Kashyap, Vipul" <VKASHYAP1@PARTNERS.ORG>, public-semweb-lifesci@w3.org
>On 5 Mar 2007, at 17:37, Kashyap, Vipul wrote: > >> >>Thanks for the response, Pat, That's quite a relief to hear. >> >>________________________________ >> >>>>EquivalentClass(X, intersectionOf(Y, Restriction(locatedinBrainRegion >>>>allValuesFrom(Z)) >>>> >>>>Is this what you had in mind? >>>>I guess, one could define macros (using the lisp backquote mechanism) where >>>>these variables could be plugges in at run time and then sent to the OWL >>>>reasoner. >>>> >>>>As long as these variables are instantiated, you are OK, but without >>>>instantiation you end up in higher order >>>>logics, which might be beyond OWL full. >>>>So that will not be feasible. >> >>Whoa. This isn't higher-order, even with >>variables. In fact its within OWL-DL, which is a >>tractable subcase of first-order. >> >>[VK]... The fact that X, Y, and Z range over classes (and laziness >>:)) is what >>made me think that. >>Glad to heat that this is not the case. > >If those do range over classes, then the above expression is, >indeed, at least syntactically second order and definitely not in >OWL-DL. Whoops. Yes, of course. I thought those were what one might call metasyntactic variables, not quantified. I reacted too quickly. Thanks for the correction, Bijan. Pat > >Depending on exactly what you wanted to do with that, especialy if >the procedural account above is what you want, then this is fairly >straightforward. > >E.g., is the above a *query*? As long as the variables range over >atomic classes (i.e., named classes), it's pretty easy. You do have >to loop over all the tuples and check if the resultant expression is >entailed (i.e., you are treating it as a certain sort of axiom >schema). You can do a better by being clever about your testing >(e.g., if replacing X with C1 is entailed for some given value of Y >and Z, and C2 is known to be disjoint with C1, then you don't need >to do a full test iwth C2 for X for those Ys and Zs.) Inside the >reasoner, you could make use of other optimizations which are used >in classification. > >Cheers, >Bijan. -- --------------------------------------------------------------------- IHMC (850)434 8903 or (650)494 3973 home 40 South Alcaniz St. (850)202 4416 office Pensacola (850)202 4440 fax FL 32502 (850)291 0667 cell phayesAT-SIGNihmc.us http://www.ihmc.us/users/phayes
Received on Monday, 5 March 2007 20:53:28 UTC