Re: shapes-ISSUE-18 (S35 examples): S35 needs to state what constraints are required

On Dec 19, 2014 5:01 AM, "RDF Data Shapes Working Group Issue Tracker" <
sysbot+tracker@w3.org> wrote:
>
> shapes-ISSUE-18 (S35 examples): S35 needs to state what constraints are
required
>
> http://www.w3.org/2014/data-shapes/track/issues/18
>
> Raised by: Peter Patel-Schneider
> On product:
>
> S35
https://www.w3.org/2014/data-shapes/wiki/User_Stories#S35:_Describe_disconnected_graphs
talks about constraints over disconnected graphs.  However, it does not
state why disconnected graphs are different from connected graphs?  Are the
constraints supposed to recognize disconnected graphs?  Or are the
constraints just supposed to work on disconnected graphs, and what
differences in constraint handling are required for disconnected graphs.
>
> SPIN and OWL constraints don't care whether a graph is connected or
disconnected.

I'm trying to understand this last statement. If I had an OWL CWA/UNA
engine, I could presumably use something like OWL API to ask if a
particular node conforms to some class (as a shape) definition. There's no
mechanism in OWL that would enable that verification process to reach any
node not connected to that started node. One would simply have to verify
both nodes or invent some sort of packaging language which would entail
both verifications.

Likewise SPIN would depends on essentially separate verification processes
kicked off by some mechanism to connect the starting nodes to some shapes.

This is essentially a proposed requirement for the mechanism which triggers
verification/validation (regardless of whether it's used for validation or
description).