Thank you Andy, Dan, and Martynas for confirming this--much appreciated. --Jeff
On 12/5/20, 4:28 AM, "Andy Seaborne" <[email protected]> wrote: unlabelled [] form on its own can only represent a tree. A node in such a graph can't have two "in" arcs. Nothing specific to RDF syntax here - see JSON and XML. Any sharing needs a pointer in some way. Applies to DAGs and cycles. You can mix labelled and unlabelled forms. Jena pretty prints your example using one label: <a> ex:relates _:b0 . _:b0 ex:relates [ ex:relatedBy _:b0 ; rdf:type ex:bar ] ; rdf:type ex:foo . Andy On 04/12/2020 20:54, Dan Brickley wrote: > see also > https://www.w3.org/TR/turtle/#unlabeled-bnodes > > > > On Fri, 4 Dec 2020 at 20:20, Martynas Jusevičius <[email protected]> > wrote: > >> I don't think you can use the [ ] form to create cycles. >> >> On Fri, Dec 4, 2020 at 8:53 PM Jeffrey Kenneth Tyzzer >> <[email protected]> wrote: >>> >>> Hi, Group. >>> >>> Consider this small model: >>> >>> a --relates--> b >>> b --relates--> c >>> b <--relatedBy-- c >>> >>> Note that the b to c relationship is reciprocal. >>> >>> I’d like to represent b and c as blank nodes. Using the label form, it’s >> seemingly straightforward (I’ve added a couple of additional rdfs:type >> triples to fill-out a bit what I show next): >>> >>> a ex:relates _:b >>> _: b rdfs:type ex:foo >>> _:b ex:relates _:c >>> _:c rdfs:type ex:bar >>> _:c ex:relatedBy _:b >>> >>> Using the abbreviated form, though, doesn’t seem possible : >>> >>> a ex:relates [ rdfs:type ex:foo ; ex: relates [ rdfs:type ex:bar ; >> ex:relatedBy <what would go here to refer to the first (outer) blank node?> >> ] ]. >>> >>> I suppose I’m asking if something can be both the container and >> contained, but perhaps there’s some syntactic sugar/legerdemain (or >> Jena-specific syntax) I’m not aware of that makes this possible. >>> >>> Thanks. >>> >>> --Jeff >> >
