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Re: blank predicates

From: Margaret Warren <mm@zeroexp.com>
Date: Sun, 29 Mar 2020 12:47:13 -0400
To: public-lod@w3.org
Message-ID: <4607e4dc-7c73-c3ba-1e46-fe3b9a76c86b@zeroexp.com>
Pat, Melvin and All:

On the subject of 'Crap URI's (relations)' ...I have to say that I first 
used this expression in a conversation when I was demo'ing ImageSnippets 
to Timbl last year; so I will take responsibility for coining this 
'crap' term. Thank you :-)


On 3/29/2020 12:07 PM, Melvin Carvalho wrote:
> On Sun, 29 Mar 2020 at 08:43, Patrick J Hayes <phayes@ihmc.us 
> <mailto:phayes@ihmc.us>> wrote:
>     Generalized RDF allows blank nodes in relation position, so does
>     N3 and also ISO Common Logic (all with the same semantics). The
>     various suggestions to use a ’crap’ URI such as lio:relation can
>     be seen as skolemizations of these bnodes in predicate position.
>     There are independent reasons for using generalized RDF syntax in
>     any case, since reasoning is incomplete without it. And it is
>     pretty trivial to implement: it amounts to not performing some
>     syntax checks that RDF requires.
> Thanks Pat, so we could perhaps say 'crap URIs DO change' :P
> So I like turtle and N3 alot.  I'd like to use this feature of N3, but 
> am probably going to serialize in turtle in the short term
> This is exactly the information I wanted
> If I have to use a 'crap' URI in turtle, I would want it to say "this 
> is a place holder for the equivalent N3 construct".  Could we make 
> that in the N3 community group perhaps?
> I suppose nothing like that exists right now.  Would it maybe be a 
> good idea to collect the different suggestions and see which has mind 
> share at the moment?  Perhaps a straw poll.
> Regarding reification, that's a nice idea.  I worry about (perhaps 
> perceived) added compleity in serialization and querying.
> Seems a paradoxical problem.  There are too many ways to name the 
> nameless thing! :)
>     Pat Hayes
>     > On Mar 28, 2020, at 3:52 AM, 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 Sunday, 29 March 2020 16:47:27 UTC

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