Re: D-entailment question in

FWIW, I had similar concerns to Axel's with the term "identify", which I 
raised in issue-145:
Pat explained some of the rationale, but I still thought further 
clarification about the use of "identify" would help.  I explained why, 
and I made a suggestion for clarification:
However, I don't see any response to to that suggestion.  Maybe it was 


On 01/31/2014 12:51 PM, Pat Hayes wrote:
> On Jan 30, 2014, at 11:38 AM, Axel Polleres <>
> wrote:
>> Hi Richard,
>> (not meant to open a new comment, but just to re-explain my
>> original comment)
>> On 28 Jan 2014, at 09:35, Richard Cyganiak <>
>> wrote:
>>> Axel,
>>> (Not an official WG response)
>>> The definitions you're looking for are in RDF 1.1 Concepts.
>> understood, I am fine with the definitions in that document, but
>> let me re-explain why I was confused:
>>>> a) to add more explanatory text or pointers to other specs to
>>>> make these definitions more self-contained.
>> I meant to say it would be nice if there were some more links to
>> the CONCEPTS document or within the MT document to definitions
>> (editorial)
> I will work through the document and see if I can make the linking
> more transparent.
>> , e.g. the word “datatype” in the old RDF-mt spec is directly
>> linked to the definition
>> (which was within the document itself, not a part of the Conepts
>> document, which may have confused me)
> There is a convention being used here, that internal document links
> go to the exposition of the relevant idea in that document, and links
> from there go to other documents, if required. The cost of this to
> readers is that they may have make two clicks, but the opposite
> convention would mean that the links would short-circuit the
> explanatory prose in the document itself.
> A similar editorial style is used for references, where the link in
> the text goes not to the cited work itself, but to the reference
> section of the document, where there is an external link to the
> publication.
>> … if you move the definition to the Concepts doc, that’s ok, but at
>> the moment the choice between explicit references to the concept
>> document at some places, e.g. "RDF literals and datatypes are fully
>> described in Section 5 of [RDF11-CONCEPTS]” and linking directly
>> whenever you use a concept defined herein or in the concepts
>> document (such as “datatype”, defined in CONCEPTS, “L2V” defined
>> herein, but also somewhat in CONCEPTS, though less formally) seems
>> a bit arbitrary at the moment and it would be nice if this was a
>> bit more consistent.
>>>> b) explain, even if only in an informal section, how custom
>>>> datatypes should be defined (which several existing RDF
>>>> datasets do)
> << As an aside, I fail to see the relevance of the above point about
> custom datatypes to your next point about "identify". >>
>> Particularly, I am not too happy with the definition of the verb
>> “identify”
>> which,
>> frankly is more confusing than enlightning to me…
> This is not so much a definition, as a statement that we are using
> that word so as to conform to its usage in many other Web
> publications.
> Let me give an example. Someone might wish to say (in fact, we did
> not decide to say this, but someone might) that all IRIs in a certain
> class should be understood to denote the resource that responds with
> a 200-level coded response when an HTTP GET is executed using that
> IRI. This is widely, even standardly, described by saying that the
> IRI "identifies" that resource, so we could phrase this convention as
> the rule that an IRI in this class shall *denote* whatever it
> *identifies*, and treat this as a constraint upon interpretations.
> But in order to be able to even say such a thing, the concepts of
> "denote" and "identify" must be conceptually distinguished. The
> semantics document owns the term "denote" for IRIs used in RDF: it
> *defines* RDF denotation. But it recognizes that other sources and
> authorities may also define normative mappings from IRIs to what are
> regarded as their meanings, mappings which it can relate in various
> ways to the denotation mappings it is defining. The word "identify"
> is being used as a general catch-all term for any such externally
> described and conventionally recognized Web naming relationship.
> The application of this usage for datatypes is that we want to say
> that the relationship of an IRI denoting a datatype, to the datatype
> it denotes, is established by normal Web conventions external to RDF.
> We sketch this in the document as follows:
> "In practice, this can be achieved by the IRI linking to an external
> specification of the datatype which describes both the components of
> the datatype itself and the fact that the IRI identifies the
> datatype, thereby fixing a value of the datatype map of this IRI."
> If anyone wishes to know how to do this in more detail, I would
> recommend that they read the XML Schema part 2 documents and use them
> as a model.
>> "IRI meanings may also be determined by other constraints external
>> to the RDF semantics; when we wish to refer to such an externally
>> defined naming relationship, we will use the word identify and its
>> cognates.”
>> in a way, it seems that this wants to tell me that IRIs i may be
>> interpreted as different things
> No, that is not what it wants to tell you (and I confess that I do
> not understand how those words could be interpreted in that way.)
> What it says is that the meaning of an IRI may be determined by
> something outside the RDF semantics. That does not imply that the IRI
> has multiple meanings. (You do agree, I take it, that this can
> happen, ie that forces external to RDF can, on occasion, determine
> the intended meanings of IRIs?)
>> (as a resource and as a datatype), where the term “identify” seems
>> to be used to implicitly define the (fixed?) interpretaiton
>> function for a datatype, let’s call it I_datatype() but the spec
>> gives only a formal account for I_resource(i), but not for
>> I_datatype(i), whereas it DOES seem to say that I_resource(i) =
>> I_resource(j) implies that I_datatype(i) =  I_datatype(j)
>> I find the mix of informal and formal definitions here a bit hard
>> to grasp, coming from the IMO fairly clean definition of datatype
>> maps in the old RDF spec.
> The semantic Web *is* a mixture of formal and informal, however, and
> sometimes we have to face up to that reality :-)
> Pat
>> HTH to make my comment mor concrete, Axel
>>> A good understanding of Concepts is sort of a prerequisite for
>>> any of the other specs.
>>> Best, Richard
>>>> On 28 Jan 2014, at 07:53, Axel Polleres
>>>> <> wrote:
>>>> Dear RDF 1.1 WG,
>>>> First of all let me thank the WG for their efforts and work on
>>>> gettin the new RDF1.1 spec to PR. My new affilation
>>>> organization (WU Wien) has recently joined W3C and I have
>>>> started looking in a bit more detail into the new specs.
>>>> When looking over the definition of D-entailment, and also
>>>> related comments on the list, I have some small question:
>>>> If I see it correctly, and that’s good news, D-entailment is no
>>>> longer stacked on top of RDFS Entailment. I very much welcome
>>>> this change. Next, I wonder only about one thing regarding the
>>>> removal of datatype maps. As I understand the discussions, the
>>>> intention here is to simplify things, by assuming that known
>>>> IRIs *identify* datatypes, i.e. there is a fixed interpretation
>>>> for such known IRIs, and that this fixed interpretation of a
>>>> datatype IRI aaa is associated with a known lexical-to-value
>>>> mapping L2V.
>>>> However, Section 7.1 seems to have no pointers to a
>>>> *definition* of what is a *datatype* or a *lexical-to-value*
>>>> actually is, nor give any information of how a custom datatype
>>>> is defined, e.g.
>>>> "For every other IRI aaa in D, I(aaa) is the datatype
>>>> identified by aaa, and for every literal "sss"^^aaa,
>>>> IL("sss"^^aaa) = L2V(I(aaa))(sss)”
>>>> seems to miss that L2V is the associated lexical-to-value
>>>> mapping for I(aaa).
>>>> Also, I find the remote definition of *identify* in section 4
>>>> ("when we wish to refer to such an externally defined naming
>>>> relationship, we will use the word identify and its
>>>> cognates.”) insufficient to give a proper definition to what a
>>>> datatype is.
>>>> I would kindly ask the group for two things: a) to add more
>>>> explanatory text or pointers to other specs to make these
>>>> definitions more self-contained. b) explain, even if only in an
>>>> informal section, how custom datatypes should be defined (which
>>>> several existing RDF datasets do)
>>>> If I understand this correctly, such informal addition as well
>>>> as adding explaining text or references to other specs
>>>> containing the resp. definitions would not be a substantial
>>>> change, and not affect PR status.
>>>> best regards, Axel
>>>> -- Prof. Dr. Axel Polleres Institute for Information Business,
>>>> WU Vienna url:  twitter:
>>>> @AxelPolleres
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Received on Monday, 10 February 2014 14:31:22 UTC