Re: recursion in SHACL

Thank you for catching that Peter.
Since issue 22 is still open I only added issue warning whenever recursion
is mentioned in the spec.
The updates are not online yet but you may look at the diff here

On Mon, Mar 7, 2016 at 9:05 PM, Peter F. Patel-Schneider <> wrote:

> On 16 Dec 2015 the working group approved the resolution
> RESOLUTION: The starting point for recursion in SHACL is that shapes graphs
> with dependency loops are invalid, suitable limitations of this will be
> explored
> The SHACL document currently says
> A shape may refer to itself directly or indirectly via sh:valueShape,
> sh:filterShape, etc. Such a shape is said to be recursive. The meaning of
> non-recursive shapes is always well-founded. In contrast, the meaning of a
> recursive shape may not be well-founded. As a starting point, the SHACL
> specification only defines the meaning of non-recursive shapes. However,
> there
> are use-cases where recursion is valuable, either for its inherent
> expressive
> power or because it makes the intension of shapes clearer. The Working
> Group
> will therefore explore conditions under which recursive shapes can be
> assigned
> a well-defined meaning and will relax the restrictions on recursion
> accordingly.
> This paragraph does not match with the resolution.
> peter

Dimitris Kontokostas
Department of Computer Science, University of Leipzig & DBpedia Association
Projects:,, http://
Research Group: AKSW/KILT

Received on Saturday, 12 March 2016 05:23:04 UTC