W3C home > Mailing lists > Public > public-rdf-wg@w3.org > November 2012

Re: [Moderator Action] Sloppy inference rules

From: Tim Berners-Lee <timbl@w3.org>
Date: Mon, 19 Nov 2012 15:29:11 +0000
Cc: Richard Cyganiak <richard@cyganiak.de>, Pat Hayes <phayes@ihmc.us>, Guus Schreiber <guus.schreiber@vu.nl>, RDF WG <public-rdf-wg@w3.org>
Message-Id: <2578D2EC-E760-4E02-B861-27A2EBDB8000@w3.org>
To: nathan@webr3.org
In general,  I think this is going in a better direction.

1)  A bnode as a predicate is, I find, sometimes valuable.  It doesn't change the RDFs of things, it does allow to state things about the predicate without having to invent URIs on the fly which is sometimes (a) a pain to go in running code and (b) a deliberate wish not to make something you have to then support and nurture as a public Property.

<JoesHomePage.html>   [  sandro:parallelProperty fb:likes  ]  <RockyHorrorShow.html> .

:Alice  [ is owl:inverseOf  ex:supervisor ]  :Bob.

Bnode Properties, though not in the predicate slot in the statement, the tabulator
will use if it find something like:

:child a property, rdfs:label "parent", owl:inverseOf [rdfs:label "parent" ].

2) Literals as predicates? No thanks.

In a view of the world I find convenient, literals and properties
are disjoint.

Also I assume

{   ?s ?p ?o } => { ?p a rdf:Property }.

So to say

	Alice 3 Bob

would give an inconstancy.  You could say it wasn't the RDF graph level.

So I'd be content to see parsers which accepted a number as a property I suppose,
but my system would flag it as an error at the next stage.

It is good to be able to flag it as an error, as Turtle is getting 
toward the undesirable state for a language where 
almost anything you write will parse, and so ability to trap typos is reduced.

Another reason I would really want to keep predicates distinct form any literals 
would be in the UI in user input mode I want to give the user, when choosing say a form field or predicate value for a new relationship, a choice of Properties 
but I really don't want to have to give choices of literal values!


On 2012-11 -07, at 06:23, Nathan wrote:

> Richard Cyganiak wrote:
>> On 30 Oct 2012, at 16:15, Pat Hayes wrote:
>>> So my question to the WG is, how disastrous would it be if the RDFS inference rules were stated in terms of a 'sloppy' version of RDF with the syntactic restrictions removed, i.e. with the following grammar for triples?
>>> triple ::= term term term .
>>> term ::=  IRI | blanknode | literal
>> +1
> +1
Received on Thursday, 22 November 2012 17:34:34 UTC

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