On Mar 29, 2014, at 8:10 PM, Peter F. Patel-Schneider <pfpschnei...@gmail.com> wrote:
> > On 03/29/2014 03:30 PM, Markus Lanthaler wrote: >> On Wednesday, March 26, 2014 5:26 AM, Pat Hayes wrote: >>> Hmm. I would be inclined to violate IRI opacity at this point and have >>> a convention that says that any schema.org property schema:ppp can have >>> a sister property called schema:pppList, for any character string ppp. >>> So you ought to check schema:knowsList when you are asked to look for >>> schema:knows. Then although there isn't a link in the conventional >>> sense, there is a computable route from schema:knows to >>> schema:knowsList, which as far as I am concerned amounts to a link. >> Schema.org doesn't suffer from this issue as much as other vocabularies do >> as it isn't defined with RDFS but uses its own, looser description >> mechanisms such as schema:domainIncludes and schema:rangeIncludes. So what >> I'm really looking for is a solution that would work in general, not just >> for some vocabularies. >> [...] >> >> >> -- >> Markus Lanthaler >> @markuslanthaler >> > I would like to see some firm definition of just how these looser > description mechanisms actually work. Yes, I agree. Let me put the question rather more sharply. What follows from knowing that ppp schema:domainIncludes ccc . ? Suppose you know this and you also know that x ppp y . Can you infer x rdf:type ccc? I presume not, since the domain might include other stuff outside ccc. So, what *can* be inferred about the relationship between x and ccc ? As far as I can see, nothing can be inferred. If I am wrong, please enlighten me. But if I am right, what possible utility is there in even making a schema:domainIncludes assertion? If "inference" is too strong, let me weaken my question: what possible utility **in any way whatsoever** is provided by knowing that schema:domainIncludes holds between ppp and ccc? What software can do what with this, that it could not do as well without this? Having a piece of formalism which claims to be a 'weak' assertion becomes simply ludicrous when it is so weak that it carries no content at all. This bears the same relation to axiom writing that miming does to wrestling. Pat > > peter > > ------------------------------------------------------------ IHMC (850)434 8903 home 40 South Alcaniz St. (850)202 4416 office Pensacola (850)202 4440 fax FL 32502 (850)291 0667 mobile (preferred) pha...@ihmc.us http://www.ihmc.us/users/phayes