- From: Peter F. Patel-Schneider <pfpschneider@gmail.com>
- Date: Fri, 03 Apr 2015 07:05:20 -0700
- To: Arthur Ryman <arthur.ryman@gmail.com>, Richard Cyganiak <richard@cyganiak.de>
- CC: "public-data-shapes-wg@w3.org" <public-data-shapes-wg@w3.org>
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Punning was introduced in OWL 2 to allow for RDF graphs where IRIs are used as both classes and individuals. At the time OWL 2 was designed it was not known whether it was possible to build effective OWL reasoners when inference about individuals (particularly equality) could affect the ontology (particularly implying that two classes are equal). I think that the idea for punning in SHACL is to allow for RDF nodes that denote both a shape and a class while still keeping these two identities apart. In this way stating that the type of an individual is a class&shape would not trigger any shape-based stuff, because typing would be on the class identity, not the shape identity. I don't like using punning for this purpose. For starters, I think that it will be hard to describe to users. I much prefer a clean distinction between classes and conditions/constraints/shapes. peter On 04/02/2015 01:20 PM, Arthur Ryman wrote: > Richard, > > Thx. I believe that OWL needed to introduce punning because in strict > Description Logic there is a partitioning of resources into disjoint > sets, i.e. Class, Property, Individual. > > I don't believe that we are basing SHACL on DL. Therefore there is no > problem with SHACL triples having a their subject as a Class. Is there > some problem with this? What am I missing? Do you imagine that a SHACL > engine would need some way to distinguish a Shape from a Class? i.e. > given an IRI, if it's a Class to one thing else if it's a Shape do some > other thing? > > -- Arthur > -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAEBAgAGBQJVHp4gAAoJECjN6+QThfjzP60IAM9W9icHgbGWPv1c6EiLB/iF 97eC4OiVdP6Y+4lBfmPC31rNSlIcyLdc7feeIIV+7zzYbx2lken9lehZzo+L9Cuh IuFX4DYIw8apH4G48KUy3qXQQdtOmrDoaztmrdaoXv5bQJKVqmYKe/cri+i2wHnX bTwkSElpHcoGH0j4tKo1RowaNeTDC8j6lA33oB8HiwiUEKPF+u6TKLjHenk1NqmE vn2AkIuhuy45G+yZuuRQ+AoBnNmaDsTpKhdY5hbUPNt44T1tnorjn5EtUb6Fo6sv Ti4tu57pjL/mnBOJ4OCYnB3VhtL5ZOla2ss3vw0MO8uMhIt/hyhj4q1NRyVDi4w= =pXSK -----END PGP SIGNATURE-----
Received on Friday, 3 April 2015 14:05:53 UTC