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Re: blank predicates

From: Tim Berners-Lee <timbl@w3.org>
Date: Wed, 6 May 2020 08:50:41 +0100
Message-Id: <F35546E7-24ED-444B-BAFB-DDA20D8DA19A@w3.org>
Cc: Dan Brickley <danbri@danbri.org>, public-lod <public-lod@w3.org>
To: Melvin Carvalho <melvincarvalho@gmail.com>

> On 2020-03 -28, at 10:03, Melvin Carvalho <melvincarvalho@gmail.com> wrote:
> On Sat, 28 Mar 2020 at 10:53, Dan Brickley <danbri@danbri.org <mailto:danbri@danbri.org>> wrote:
> there are an infinite number of boring relationships that hold between any arbitrary pair of objects; your best bet might be to name one for your application rather than attempt to use generalized (predicateless) rdf
> So maybe simply <> ?

Not <> as it the current document.

But [ ] in fact is a good idea.  It is a bnode.
In N3 and rdflib.js you can have bnodes as predicates.

Or you can give it a URI even though you don’t know much about it.

:Alice [  a ex:FamilyRelationship ] :Bob .

means there is some relationship with Bob where that relationship in in the class ex:FamilyRelationship even though you don’t know yet exactly what it is.

It’s a bit obscure, and basic RDF doesn’t allow it.  

Of course in SPARQL you can use variables.

:Alice  ?pred :Bob .
?pred a ex:FamilyRelationship . 

Or just as somebody said give it a name anyway

:Alice  :AliceBobRel :Bob .
:AliceBobRel a ex:FamilyRelationship . 

and addd more info as you learn more.

various options. 


> #Alice <> #Bob .
> Dan
> On Sat, 28 Mar 2020 at 08:57, Melvin Carvalho <melvincarvalho@gmail.com <mailto:melvincarvalho@gmail.com>> wrote:
> I am working on a information mapping system (aka mind maps)
> And I want to have two nodes related to each other
> #Alice R #Bob
> In the general sense, the type of relationship (predicate) R is not really known at the time of creation.  My software currently does not allow the labeling of edges is the reason (but hopefully in future it will)
> I need a way to relate Alice to Bob but I dont have a URI for a predicate.
> Is there something that can operate as a "blank predicate"?  
> Or some existing relations that simply says that two entities or linked / related, without yet knowing how they are related?

Received on Wednesday, 6 May 2020 07:50:47 UTC

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