W3C home > Mailing lists > Public > public-rdf-comments@w3.org > February 2014

Re: Formal Objection to RDF Working Group resolution of issue 165

From: Ivan Herman <ivan@w3.org>
Date: Tue, 25 Feb 2014 16:26:07 +0100
Cc: "public-rdf-comments@w3.org Comments" <public-rdf-comments@w3.org>, W3C Chairs of RDF WG <team-rdf-chairs@w3.org>, Tim Berners-Lee <timbl@w3.org>
Message-Id: <645973D9-1DD2-4784-AB8F-39E0792F971D@w3.org>
To: Michael Schneider <schneid@fzi.de>
Dear Michael,

As you may have seen, the RDF 1.1 Recommendations have just been published. The official mail sent to the AC representatives also includes a reaction to this mail as follows:

[[[
As reported in the Call for Review, Michael Schneider raised an objection  
that was not upheld by the Director. The objection was reiterated in a  
public email [2]. The Director has discussed the objection with the  
Working Group Chairs and the Team Contact, and supports their  
determination that the Working Group has considered the issue fully.
]]]

Ivan





On 09 Feb 2014, at 23:49 , Michael Schneider <schneid@fzi.de> wrote:

> To the director of the W3C,
> to the chairs and W3C team members of the RDF Working Group,
> to the members of the RDF Working Group,
> and to anyone else to whom it may concern.
> 
> This is a formal objection to a change made to the semantics of
> datatypes in the Proposed Recommendation of the RDF 1.1 Semantics.
> The change concerns the replacement of the original concept of
> a "datatype map" by the concept of a "set of recognized datatype
> IRIs". I will argue that this change is largely unmotivated and
> unnessesary, technically incompatible with the original concept,
> questionable and even flawed, and may lead to diverse problems
> for dependent Semantic Web standards and other dependent work.
> My proposal will be to revert the change to the original
> definition as of 2004 and to postpone further discussion of
> the change to a future RDF Working Group. This formal objection
> follows my reviews of earlier versions of the RDF 1.1 Semantics
> and my discussions with the RDF Working Group about the same
> topic, which did not lead to a satisfiable conclusion for me.
> 
> Michael Schneider,
> Frankfurt am Main (Germany), 9 Febrary 2014
> 
> 
> == Introduction ==
> 
> This is a formal objection to a change made by the RDF Working
> Group to the semantics of datatypes in the RDF 1.1 Semantics
> compared to the original RDF Semantics specification as
> of 2004 (from now on called "RDF 2004") [01]. The formal
> objection targets the Proposed Recommendation (PR) of the
> RDF 1.1 Semantics [02], which still underwent some changes
> compared to the previous versions of the document, and which
> is now intended by the Working Group to become the final
> recommendation. The formal objection follows my reviews
> of earlier versions of the RDF 1.1 Semantics and my
> discussions with the RDF Working Group about the same
> topic [03][04], which did not lead to a satisfiable
> conclusion for me [05]. I have to point out that this formal
> objection is not made by an official W3C member organisation,
> and none of the organisations I am affiliated with
> or in some current relationship with has is involved.
> Rather, the formal objection is made by me as a private person,
> and as a member of the informal Semantic Web community,
> who has considerably contributed to the Semantic Web initiative
> in the past and has a strong background and a stake
> particularly in the RDF Semantics; see the section
> "About the Author" for information about me.
> 
> The change to which I formally object concerns the replacement
> of the original concept of a "datatype map" in Chap. 5 of [01]
> by the concept of a "set of recognized datatype IRIs"
> in Chap. 7 of [02]. In the original RDF 2004 Semantics,
> a datatype map has been a set of associations between datatype
> IRIs (originally URI references) and datatypes. In the RDF 1.1
> Semantics PR, there is now a "set of recognized datatype IRIs",
> that is, only the datatype IRIs, together with the additional
> requirement of the existence of a globally unique mapping
> between datatype IRIs and datatypes (where this unique mapping
> is not intended to be fully defined by the RDF 1.1 spec).
> I will describe the chnge in more detail in Section
> "Description of the Change".
> 
> I will first argue, in Section "A Non-Editorial Change", that the
> change is not simply an editorial change, and will give arguments,
> in Section "Missing Motivation and Necessity for the Change", why
> I consider the change unmotivated and unnecessary. In Section
> "Technical Consequences of the Change", I will list what I
> consider the most relevant technical consequences of the change,
> and will also give examples for possible practical consequences.
> I will then, in Section "Consequences for dependent Semantic Web
> Standards and other Work", argue that the change may have
> unfortunate consequences for other existing Semantic Web Standards,
> which are based on RDF, such as OWL 2, SPARQL 1.1, and RIF,
> and may possibly lead to a split situation, where some of future
> versions of these standards will adopt the change made in RDF
> while others may not.
> 
> Finally, in Section "Conclusions and Proposal", I will summarize
> my arguments and argue that the consequences to be expected from
> the change are strong and undesiarable, and would not exist if
> the original notion of datatype maps would have been retained.
> Consequencly, I will propose to revert the change to the original
> situation as of RDF 2004, and to postpone further discussion of
> the change to a future RDF Working Group.
> 
> 
> == Description of the Change ==
> 
> RDF 2004 introduced the concept of a "datatype map", "being a set
> of pairs of a IRI and a datatype such that no IRI appears twice
> in D" (Chap. 5 of [01]; note: in order to ease the discussion,
> I use the term "IRI" everywhere, although the RDF 2004 spec used
> the term "URI reference" instead.) In the current PR of the
> RDF 1.1 Semantics, D is not a set of IRI-datatype pairs anymore,
> but a set of datatype IRIs only (Chap. 7 of [02]). It is also
> not called a "datatype map" anymore, but is now called a
> "set of recognized datatype IRIs".
> 
> The RDF 1.1 Semantics further states that (a) "the semantics
> presumes that a recognized IRI identifies a unique datatype
> wherever it occurs", and (b) that "the exact mechanism by
> which an IRI identifies a datatype is considered to be
> external to the semantics" (beginning of Chap 7).
> The second Change Note in Chap. 7 informally elaborates
> on this statement by saying that "the current semantics
> presumes that a recognized IRI identifies a unique datatype,
> this IRI-to-datatype mapping is globally unique and externally
> specified". In contrast, RDF 2004 did not require a globally
> unique association between datatype IRIs and datatypes.
> Rather, the definition of datatype maps made it possible to
> have IRI-datatype associations being unique only locally with
> regard to a particular datatype map D, or, likewise, locally
> unique to an entailment regime that uses a particular datatype
> map D.
> 
> To illustrate the difference, consider the case of a custom
> definition of D-RDFS with D including a new custom datatype.
> In RDF 2004, it was possible to associate the the same IRI
> to one datatype in one datatype map D1 and to a different
> datatype in another datatype map D2. For example, the IRI
> "ex:complex" may have been associated to a datatype
> representing the mathematical field of complex numbers
> in one extension of RDFS, and to a datatype representing
> four-dimensional composites of real numbers for the
> representation of space-time events in another extension
> of RDFS. Under the RDF 1.1 Semantics, which requires the
> existence of a globally unique IRI-datatype association,
> this will not be possible anymore (regardless what the
> globally unique IRI-datatype association will look like,
> which is, as cited above, not fully determined by the
> RDF 1.1 standard).
> 
> In addition, some of the semantic conditions related to
> the semantics of datatype have been adjusted in order to
> reflect the change mentioned above on a technical level.
> In general, the semantic conditions now refer to applications
> of a given interpretation I to a datatype IRI aaa, "I(aaa)",
> instead of referring to the associated datatype by its
> reference given in the datatype map, as was done in RDF 2004.
> For example, compare the second of the Semantic conditions
> for datatype literals in Chap. 7 of [02] with the third of
> the General semantic conditions for datatypes in Chap. 5
> of [01].
> 
> To summarize, the whole change here includes:
> 
>  * a change in nomenclature:
>    ("datatype map" vs. "set of recognized datatype IRIs");
> 
>  * a change in the formal representation of the objects
>    under consideration: a set of IRI-datatype pairs vs.
>    a set of IRIs only plus an additional globally unique
>    IRI-datatype association, together with adjustments
>    to the semantic conditions for datatype semantics;
> 
>  * a change to the scope of uniqueness of IRI-datatype
>    associations: this scope has been local to every
>    particular datatype map in RDF 2004 while being global,
>    and by intention mostly undetermined, in RDF 1.1.
> 
> 
> == A Non-Editorial Change ==
> 
> It has been argued by the Working Group that the change is of
> a purely editorial nature. I would certainly not formally
> object to an editorial change, but consider this a non-editorial
> change. An editorial change would not change basic nomenclature
> or formal or technical aspects of a specification, and all this
> is the case here.
> 
> Firstly, as stated above, the change introduced a change in
> nomenclature from the notion of a "datatype map" to the notion
> of a "set of recognized IRIs". Secondly, there have been some
> changes to the underlying formal representation, as listed above.
> Thirdly, and most notably in my opinion, the change of scope of
> uniqueness of IRI-datatype associations has changed. This change
> does have measurable effects, as I have already pointed out
> by my example above where the same IRI "ex:complex" is used
> for different datatypes: this is clearly possible in RDF 2004,
> but will not be possible anymore in RDF 1.1.
> 
> Another way of looking at the question whether a change to a
> specification is editorial or not is to check whether existing
> dependent work, such as other specifications, scientific papers,
> or text books, would need to be updated in non-trivial ways
> in order to be in line again with the changed specification.
> For the change here, it becomes clear that dependent work
> needs to be updated concerning the same things that have
> changed in the RDF specification. For example, a text book
> that is of a more formal nature would probably need to change
> its used nomenclature from "datatype maps" to "sets of
> recognized IRIs", its basic definitions from sets of pairs
> IRI-datatype pairs to sets of IRIs, and would need to reflect
> the change in the scope of uniqueness of the IRI-datatype
> associations.
> 
> Based on these arguments, I conclude that the change is
> clearly non-editorial.
> 
> 
> == Missing Motivation and Necessity for the Change ==
> 
> A non-editorial change in a specification requires good
> motivation, and this is particularly true in the case of
> RDF and its semantics, for which the charta of the
> RDF 1.1 Working Group [06] explicitly requires that
> "changing the fundamentals of the RDF Semantics" are
> out of scope for the WG (Chapter 3). Based on my arguments
> given below in the text concerning technical consequences
> of the change, I consider the change to be indeed a change
> of the fundamentals of the RDF semantics, and thus in
> conflict with the charta.
> 
> In general, the scope of the RDF WG was held deliberately
> conservative. According to its charta, the scope was
> "to extend RDF to include some of the features that the
> community has identified as both desirable and important
> for interoperability based on experience with the 2004
> version of the standard, but without having a negative
> effect on existing deployment efforts." However, I am not
> aware of any input from outside the working group during
> the past 10 years since RDF 2004 became a recommendation
> that would have asked for a change of the semantics
> concerning the concept of datatype maps, or would have
> indicated any problems with this concept. Rather, within
> the previous years, at least three other core Semantic Web
> standards have been written (OWL 2, SPARQL 1.1, and RIF),
> which reuse the original notion of datatype maps without
> any known problems, each taking years of specification
> work and building up considerable experience with these
> things. I am also not aware of any discussion concerning
> problems with datatype maps from either the workshop or
> the questionnaire that had preceeded the initiation of
> the Working Group.
> 
> As far as I am concerned myself, I have been responsible
> for editing one of the mentioned dependent standards
> (the OWL 2 RDF-Based Semantics), which makes heavy use of
> the original definitions for datatype and datatype maps.
> I have also provided some technical support (both in
> private and public conversation) to the editors of
> SPARQL 1.1 Entailment Regimes and RIF RDF&OWL Compatibility
> with regard to the RDF semantics in general and to datatype
> related semantics in particular. I have further created
> several large test suites, which are to a large extent
> about datatype semantics. I have created many formal proofs
> based on the datatype semantics of RDF. I have spend some
> time thinking about the implementation of datatype semantics,
> although not yet implemented into my RDF Semantics reasoner
> called Swertia. And overall I have been working in the
> RDF field fulltime continuously for the last 8 years up to
> the day. But in all these years with all this gained
> experience concerning the RDF Semantics in general and
> RDF datatype semantics in particular, I have never
> encountered any serious problems with the original notion
> of datatype maps. Rather, I have always found the original
> datatype semantics well designed and it allowed me to do my
> work decently. I would never have come to the conclusion that
> anything would require a change, in particular not a change
> of the kind proposed in RDF 1.1.
> 
> In fact, from my earlier discussion with the Working Group
> it became apparent to me that the change was not based on
> input from the outside, as was requested by the charta,
> but only from within the Working Group. In the context of the
> charta, this would have only be acceptable, if there was a
> strong reason, such as a so far unnoticed bug. The actual
> rational of the Working Group was then to simplify the current
> presentation of the RDF semantics [07]. Having given my arguments
> above about the complete lack of request for a change and the
> much work that has been carried out without problems based on
> the original definitions, it should be clear that I do not see
> any reason here for any form of simplification with regard
> to the original situation. But of even more relevance is
> that the changes have not really "simplified" the situation,
> but have rather changed the situation and introduced
> significant technical problems, as I will point out in
> the following section.
> 
> 
> == Technical Consequences of the Change ==
> 
> Probably the most notable technical aspect of the change
> is that it is now assumed by the RDF 1.1 Semantics that there
> exists a globally unique IRI-datatype association, which is
> to be applied for each set D of recognized IRIs (as an
> integral part of an interpretation I). In comparison, no
> such unique IRI-datatype association was assumed in RDF 2004,
> but the concept of datatype maps allowed to have different
> datatype maps sharing the same IRI but associated with
> different datatypes. Further, the RDF 1.1 Semantics PR
> does not define this globally unique IRI-datatype association,
> but considers its definition to be external to the semantics,
> except for a small number of datatype IRIs from the XSD
> namespace. This difference has a number of considerable
> technical consequences.
> 
> The first technical problem is that the change strongly reduces
> the number of possible constellations of IRI-datatype associations:
> In RDF 2004, for any set of IRIs i1,...,in there were, in principle,
> infinitely many possible datatype maps D = { (i1,d1), ..., (in,dn) }.
> In RDF 1.1, however, the associated datatypes d1,...,dn are uniquely
> determined to be those from the globally unique IRI-datatype
> association, which means that there is only a single such IRI-datatype
> association for the given set of IRIs.
> 
> An example for a possible practical consequence, which I have
> already mentioned earlier, is that of two entailment regimes
> sharing the same datatype IRI "ex:complex", but associated to
> different datatypes, namely the mathematical field of complex
> numbers on one hand, and a set of compounds of four real numbers
> to represent space-time events. In general, it should be expected
> that in certain fields custom datatypes will be developed and
> used, without the need to wait for an international standardisation
> of a IRI. The problem here is that if such a situation of concurrent
> IRI-datatype associations occurs, at least one of the entailment
> regimes will not be compliant with the RDF 1.1 standard anymore,
> due to the fact that the RDF 1.1 standard demands that there is
> a globally unique datatype associated for any given datatype IRI.
> While this will hardly stop organisations from still developing
> and using their custom datatypes, the situation is annoying and
> undesirable, and it could trivially be avoided by sticking with
> the original concept of datatype maps from RDF 2004.
> 
> The second technical problem is that, as the RDF 1.1 Semantics PR
> does neither provide nor ask for an explicit set of the globally
> unique IRI-datatype association, the task of proving certain
> semantic properties, such as the soundness and completeness
> of reasoning algorithms or reasoning tools, may become problematic
> or even impossible. For example, if we have some reasoner R that
> accepts pairs of RDF graphs and outputs boolean values,
> and we ask whether R is sound and complete with regard to D-RDFS,
> for D including the datatype IRI "ex:complex", how can we proof
> or disproof whether this semantic property holds for R or not?
> As mentioned earlier, there may be more than one obvious datatypes
> associated with "ex:complex", and unless we know the "right" one,
> we simply cannot start proof work.
> 
> This has not been a problem in RDF 2004, where the proof work
> would have been done with regard to D-RDFS having an explicitly
> defined datatype map D, which would have included a reference to
> the datatype associated with "ex:complex". In fact, it would have
> been possible to have D1-RDFS and D2-RDFS, both including the
> IRI "ex:complex" but with different associated datatypes. R would
> then, perhaps, have been sound and complete w.r.t. D1-RDFS but not
> w.r.t. D2-RDFS, but, in any case, the proof work would have been
> possible technically and its result would be been perfectly
> determined.
> 
> The third technical problem is that the assumption of the existence
> of a globally unique, but completely open to an externally provided
> definition, set of IRI-datatype association breaks, strictly
> speeking, or at leasts "confuses" the RDF Semantics. As there are
> no further limitations on the set of IRIs for which there can
> be associated datatypes, there may be a datatype for
> /every possible/ IRI, including every IRI defined for other
> purposes by the RDF Semantics itself or elsewhere in the
> Semantic Web. Hence, for any given D interpretation I and
> any given IRI aaa, there exists some datatype d such that
> I(aaa) = d. This horrible semantic concequence was certainly
> not intended by the Working Group, but it is a consequence of
> missing restrictions on the set of IRIs allowed to act as
> datatype IRIs. However, I cannot imagine any meaningful constraint
> on the names of datatype IRIs, so this problem will hardly be
> eliminated by adding whatever constraint. Again, this problem
> has not existed in RDF 2004, since there has not been such an
> assumption about a globally unique but indetermined IRI-datatype
> association.
> 
> 
> == Consequences for dependent Semantic Web Standards and other Work ==
> 
> For existing Semantic Web standards that depend on the
> RDF semantics and specifically on the original notion
> of datatype maps, the change will mean that these standards
> are not fully aligned anymore with the new version of RDF.
> The most important standards that are directly affected
> in this way are:
> 
>  * OWL 2, specifically the OWL 2 RDF-Based Semantics,
>    which is a conservative semantic extension of
>    RDF 2004 D-entailment and makes strong use of the
>    original datatype semantics;
> 
>  * SPARQL 1.1, specifically the RDF 1.1 Entailment Regimes,
>    which defines query results for querying on top of the
>    different RDF 2004 entailment regimes, including D entailment
>    and the also affected OWL 2 RDF-Based Semantics;
> 
>  * RIF, specifically the RIF RDF and OWL Compatibility spec,
>    which defines RIF-X combinations, for X being any of the
>    entailment regimes defined by the RDF 2004 Semantics
>    and also the affected OWL 2 RDF-Based Semantics.
> 
> Notwithstanding the question whether the change leads to relevant
> technical consequences, there will at least be a mismatch in
> nomenclature, concepts, and formal representation. In fact, all
> listed standards above explicitly refer to the definition of
> datatype maps and use them for their own purpose.
> 
> For example, the OWL 2 RDF-Based Semantics, following the
> definitions of OWL 2 in general, introduces a specific
> minimal datatype map consisting of a required set of
> IRI-datatype associations, which even include several new
> datatypes that have been introduced for specifically for
> OWL 2 (and in part for RIF). The OWL 2 RDF-Based Semantics
> considers any reasoner that fully supports /at least/
> these IRI-datatype associations as a compliant
> OWL 2 RDF-Based reasoner, and allows such a reasoner
> to support /arbitrary/ additional IRI-datatype associations;
> which is, strictly speaking, in conflict with the idea
> of a globally unique set of IRI-datatype associations.
> 
> In general, I do not consider the change here to be of a sort
> that would easily and naturally be implemented in future versions
> of these dependent standards. It is by far not an obvious change,
> or even only a "simplification" of the original situation.
> Rather, it affects several aspects such as basic nomenclature,
> formal representation, and even semantic assumptions about the
> form of the interpretation functions. I am even unsure whether
> all future working groups for these dependent standards will
> be willing to adopt the change made to RDF 1.1, as this would
> probably bring little value for these other standard beyond
> formal compliance with RDF 1.1, but to the expense of possibly
> breaking backwards compatiblity with the original version of
> this other standard, as in the case of the OWL 2 RDF-Based
> Semantics. So we may eventually find ourselves in a situation,
> where some of the Semantic Web standards will follow the change
> taken in RDF, while other's won't. This would, of course,
> be a highly unfortunate and embarrassing situation, in
> particular as the situation would be perfectly easily avoided
> by simply avoiding the applied change to RDF in the first place.
> 
> Similar consequences as for dependent standards are to be expected
> for other existing work depending on or building on top of RDF,
> such as text books on RDF or other semantic technologies,
> university courses, research papers, software, etc.
> 
> 
> == Conclusions and Proposal ==
> 
> I have argued that the current change is a non-editorial change
> that leads to certain incompatibilities with RDF 2004
> and generally to undesirable consequences, such as
> that it restricts the flexibility of defining custom entailment
> regimes, a potential lack of well-definedness in questions
> such as about soundness and completeness for reasoning algorithms
> and tools, and even a technically flawed semantics by implicitly
> requiring any existing IRI to be interpreted as some datatype.
> This may have practical consequences for the application of
> the RDF standard, and may lead to issues for existing other
> Semantic Web standards, up to the danger of breaking compatibility
> with earlier versions of these standards, if adopted,
> or alternatively to a split situation, where some future versions
> of these standards will not adopt the change made to RDF.
> 
> I have further noted that none of these problems existed
> for the original definition of datatype maps, and that no
> other technical problems of datatype maps have been
> brought up ever since from the outside to the RDF WG,
> as originally required by the WG charta, although the
> RDF specification, and particularly the notion of datatype
> maps, has been in heavy use for a decade. In fact, the
> rational for the change was essentially to only simplify
> the original situation without any technical change.
> As I have argued, the change /is/ technical, and has
> considerable problematic consequences, while there was no
> known request in the past even for simplification - a
> point that I can well confirm as someone who has worked
> a lot with the definition of datatype maps in the past,
> including specification work, the creation of test suites,
> and formal proof work.
> 
> I therefore propose to fully revert the change to the original
> notion of datatype maps to the form as it appears in the
> original RDF specification as of 2004. This will be a valid
> operation since, as I have argued, there was nothing really
> wrong with the original definitions. It will also be a
> preferable operation, since existing Semantic Web standards
> and other published documents will continue to be compatible
> with RDF 1.1, and their future authors will not be forced
> into a decision whether to follow the change in the RDF semantics,
> or to stick with the old definitions, where either choice may
> be leading to certain compatibility issues.
> 
> I expect that such a revert will be technically and editorially
> easy, as the change is, fortunately, not very strongly entangled
> with other parts of the specification, and the changes to the
> semantics of datatypes are pretty straightforward.
> 
> However, I do not suggest to completely abondon the idea of the
> change. As there has been much discussion on the topic within
> the Working Group but essentially none outside of it, neither
> before the WG has started nor during its active time, I consider
> it purposeful to put the change to the list of postponed issues
> to be treated by a future RDF working group. By this, the proposed
> change gets the chance to become known and discussed outside the
> Working Group, and in particular by future working groups of
> other standards that are based on the RDF Semantics. I believe
> that, given the lack of request from outside the Working Group,
> there is certainly no urge of applying this change to RDF now.
> 
> 
> == About the Author ==
> 
> I have been the editor of the W3C OWL 2 RDF-Based Semantics
> specification, and have been a contributor for several of
> the other core OWL 2 specification documents, including the
> OWL 2 Mapping to RDF and the OWL 2 RL/RDF Rules profile.
> I have contributed part of the W3C OWL 2 test suite with
> a focus on RDF-based reasoning, and have also created a
> much larger version of this and several other test suites
> concerning RDF semantics-based reasoning (some of them yet
> to be published). I have provided, in both private and public
> conversation, support to the editors of the SPARQL 1.1
> Entailment Regimes and the RIF RDF and OWL Compatibility
> specification on topics concerned with the RDF Semantics.
> I have worked in several international projects with strong
> focus on semantic technologies, specifically RDF. I am also
> working on a RDF reasoning system, called Swertia,
> and have provided input to the RDF 1.1 Semantics CfI
> based on this system.
> 
> I am currently employed by the Derivo GmbH, Germany,
> which is a small company specialized in products and
> services based on semantic technologies. Since May 2013,
> I have been permanently working for our business partner SAP,
> doing work entirely dedicated to semantic technologies,
> particularly RDF, SPARQL, and OWL. I am also currently a
> guest scientist at FZI Research Center for Technologies,
> Germany, where I have been working in the past for more
> than five years, and a doctorand at the Karlsruhe Institute
> of Technology (KIT), working specifically on reasoning in
> expressive extensions of the RDF Semantics.
> 
> == References ==
> 
> [01] RDF 2004 Semantics <http://www.w3.org/TR/2004/REC-rdf-mt-20040210/>
> [02] RDF 1.1 Semantics PR <http://www.w3.org/TR/2014/PR-rdf11-mt-20140109/>
> [03] LCWD comment on ISSUE 165 <http://lists.w3.org/Archives/Public/public-rdf-wg/2013Oct/0221.html>
> [04] CR comment on ISSUE 165 <http://lists.w3.org/Archives/Public/public-rdf-comments/2013Dec/0027.html>
> [05] Resolution of ISSUE 165 <http://lists.w3.org/Archives/Public/public-rdf-comments/2013Dec/0107.html>
> [06] RDF WG Charter <http://www.w3.org/2011/01/rdf-wg-charter>
> [07] <http://lists.w3.org/Archives/Public/public-rdf-comments/2013Oct/0083.html>
> 


----
Ivan Herman, W3C 
Digital Publishing Activity Lead
Home: http://www.w3.org/People/Ivan/
mobile: +31-641044153
GPG: 0x343F1A3D
FOAF: http://www.ivan-herman.net/foaf






Received on Tuesday, 25 February 2014 15:26:38 UTC

This archive was generated by hypermail 2.4.0 : Friday, 17 January 2020 16:59:44 UTC