Supporting Arrays and Tensors

David Booth,
All,

Brainstorming, "()-collections" [2] could have their types specified using a syntax resembling that of RDF literals. As considered, for backwards compatibility, when a collection's type was omitted, it would be processed as it is today.


:entity :foo (1 2 3 4 5) .

:entity :foo (1 2 3 4 5)^^rdf:List .

:entity :foo (1 2 3 4 5)^^rdf:Seq .

:entity :foo (1 2 3 4 5)^^rdf:Array .

:entity :foo (1 2 3 4 5)^^rdf:Vector .


While this syntax idea might be a "syntactic sugar" for some collection types, it would open up possibilities for processing arrays and tensors, i.e., embedding vectors.


Best regards,
Adam Sobieski

[2] https://www.w3.org/TR/rdf12-turtle/#collections


________________________________
From: Adam Sobieski <adamsobieski@hotmail.com>
Sent: Wednesday, January 21, 2026 5:21 PM
To: David Booth <david@dbooth.org>; semantic-web@w3.org <semantic-web@w3.org>
Subject: Re: The Semantic Web and N-ary Expressions

David Booth,
All,

Thank you. I added the 2006 W3C Working Group Note you indicated to a new See Also section on that page I shared.


With respect to syntax possibilities for arrays and for the related matter of (data) tensors [1] in RDF languages, brainstorming:

:entity :embedding "0.12 0.98 -0.45"^^ex:vector .

:entity :embedding "(0.12 0.98 -0.45)"^^ex:vector .

:entity :embedding "[0.12 0.98 -0.45]"^^ex:vector .

:entity :embedding "<0.12 0.98 -0.45>"^^ex:vector .

:entity :embedding "{0.12 0.98 -0.45}"^^ex:vector .


If only one could omit the string-literal quotes and, instead, use something like {...}^^namespace:datatype for arrays and (data) tensors:

:entity :embedding {0.12 0.98 -0.45}^^rdf:vector .


What do you think? Do any other possibilities come to mind?


Best regards,
Adam Sobieski

[1] Marciniak, Piotr, Piotr Sowiński, and Maria Ganzha. "Representing and querying data tensors in RDF and SPARQL." In European Semantic Web Conference, pp. 62-66. Cham: Springer Nature Switzerland, 2025. (https://arxiv.org/abs/2504.19224)

________________________________
From: David Booth <david@dbooth.org>
Sent: Monday, January 19, 2026 10:20 PM
To: semantic-web@w3.org <semantic-web@w3.org>
Subject: Re: The Semantic Web and N-ary Expressions

On 1/19/26 18:42, Adam Sobieski wrote:
> Hello. I am pleased to share some recent ideas about ways to express
> n-ary predicate-calculus expressions in knowledge graphs using Turtle
> and TriG.
>
> https://github.com/AdamSobieski/Narratology/blob/main/Content/The%20Semantic%20Web%20and%20N-ary%20Expressions.md <https://github.com/AdamSobieski/Narratology/blob/main/Content/The%20Semantic%20Web%20and%20N-ary%20Expressions.md>

Interesting ideas!  Thanks for sharing them.  Plus I imagine you've seen
the ways described in this 2006 W3C Working Group Note:
https://www.w3.org/TR/swbp-n-aryRelations

However, in my view the problem is not that we don't have enough ways to
express n-ary predicates in RDF.  The problem is that we have too *many*
ways to do it.  Or more specifically, we do not have a *standard* way,
such that it can be supported by syntactic sugar and tools can recognize
it.  Without standardization, we have chaos.

This is one of the gaps that I hope will someday be addressed in a
successor to RDF, along with taming blank nodes and proper support for
arrays.

Thanks,
David Booth