- From: Peter F. Patel-Schneider <pfpschneider@gmail.com>
- Date: Wed, 20 May 2015 03:31:11 -0700
- To: Iovka Boneva <iovka.boneva@univ-lille1.fr>
- CC: public-data-shapes-wg@w3.org
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 As far as having a semantics that actually works goes, it appears to me that there does not need to be any restriction on negation. Full interpretations over all shape labels on all nodes should do the trick. Of course, this might change the meaning of some constructs and could easily require different complexity analyses. As far as your semantics goes, however, it may be that your non-standard treatment of negation requires that no negation depends on a loop. peter PS: I'm not sure what it would mean for a semantics to be sound. I'm assuming that you meant something like the semantics is well-defined. On 05/20/2015 12:24 AM, Iovka Boneva wrote: > Le mar. 19 mai 2015 22:26:36 CEST, Peter F. Patel-Schneider a écrit : >> -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 >> >> I don't understand why Well defined schemata are defined so closely. >> >> >> Definition [Well defined schema] >> >> A shape expression schema S is called well defined if for all negated >> shape label !T in negshapes(S), the corresponding dependency sub-graph >> dep-subgraph(T, S) is a directed acyclic graph. >> >> >> This excludes any schema where a negated shape references a >> recursively-defined shape, even if that shape does not involve negation >> in any way. > > Indeed. > > >> Is this required? > It is a sufficient condition for soundness, maybe not necessary. > > >> Would it be possible to instead just say that in a well-defined schema >> there can be no loops involving negation? > > It might be possible, however (for now) I do not know how to prove it. > Also, I do not know how the validation algorithm would go, whereas I do > have a validation algorithm for my proposal. > > -- Iovka Boneva Associate professor (MdC) Université de Lille > http://www.cristal.univ-lille.fr/~boneva/ +33 6 95 75 70 25 > -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAEBCAAGBQJVXGJvAAoJECjN6+QThfjz3oAH+gMB/xitht0VboSRPEN3c0Tl abbbg+B0ORtHbn8SGpIWsUS12+EcmJy0XyjkvI42tBYMqk9pu2VSu9gJBmRY5e5P sFyVZSvJgvAZbOLbqgsLWnB6+BtknJtinMB4ZVPUL4bTGG3EXCS1He87Rb1HCAKF X1LFaj8RXlgQFuSOkeb2A7bCRcrXHlSjBeDURuMTbC7OWNTSI7xFOLFWYW6ScBt0 dY6pYUmzyg7ZoSgepo0x5WNjPIlm5nn2c/O3a/a7lJnlQ2DBHZghgB6xlu64cCeY Ro/x3bIEAOeISIj6ngn5kNBaRYplCWaCR3lG+EjrbmLZE+LlXKbicX6A0ZruC0A= =KN3/ -----END PGP SIGNATURE-----
Received on Wednesday, 20 May 2015 10:31:44 UTC