Re: SPARQL equivalence semantics

On Nov 10, 2014 6:55 PM, "Eric Prud'hommeaux" <eric@w3.org> wrote:
>
> * Peter F. Patel-Schneider <pfpschneider@gmail.com> [2014-11-10
09:52-0800]
> > So in basic SPARQL the basic graph pattern
> >   ex:a ex:b "1"^^xsd:integer .
> > does not match the RDF graph
> >   ex:a ex:b "01"^^xsd:integer .
> >
> > In an entailment regime that includes integer as a datatype, the
> > above pattern does match the graph.
>
> In principle, if you ever found that entailment regime supported.
> Usually folks just give up and write:
>   ex:a ex:b ?o FILTER (?o = 1) # bareword is an integer
> or if they're after the leading 0s:
>   ex:a ex:b ?o FILTER (?o = "01"^^xsd:integer)

Sorry, 2nd example should have been
  FILTER (same term(?o, "01"^^xsd:integer ))
If one is specifically looking for "01".

> > peter
> >
> >
> > On 11/10/2014 09:45 AM, Eric Prud'hommeaux wrote:
> > >* Peter F. Patel-Schneider <pfpschneider@gmail.com> [2014-11-10
08:13-0800]
> > >>Well, there are multiple semantics for SPARQL 1.1 if you look at the
> > >>entailment regimes.  We could say, for example, that the semantics
> > >>of shapes/constraints are to be specified in terms of the RDFS
> > >>entailment regime for SPARQL.  This would provide a tie to SPARQL as
> > >>well as providing the right meaning for rdf:type, rdfs:subClassOf,
> > >>rdfs:domain, and rdfs:range.
> > >>
> > >>It does appear that SPARQL without entailment regimes is sensitive
> > >>to the surface form of literals.  Can anyone determine whether this
> > >>is true?
> > >
> > >SPARQL graph matching tests for RDF term equivalence per the abstract
> > >syntax. If it looks different, it, aside from "ab"@en and "ab"@EN.
> > >There are a bunch of operators that add more kinds of equivalence in
> > >expressions (FILTER and BIND).
> > >   http://www.w3.org/TR/sparql11-query/#OperatorMapping
> > >The following FILTER is true:
> > >   FILTER ("1"^^xsd:integer = "01"^^xsd:integer)
> > >You can test for pedantic (or cheap) RDF equivalence with
sameTerm(A,B):
> > >http://www.w3.org/TR/sparql11-query/#func-sameTerm
> > >
> > >
> > >>peter
> > >>
> > >>PS:  SPARQL 1.1 (the current version) is defined in terms of the
> > >>2004 version of RDF, not RDF 1.1.
> > >>
> > >>
> > >>On 11/10/2014 07:38 AM, Arthur Ryman wrote:
> > >>>Peter,
> > >>>
> > >>>I am proposing that we define the semantics of shapes/constraints in
terms
> > >>>of the data model specified in the RDF 1.1 spec. which does not
include
> > >>>classes, RDFS, etc. This is how the semantics of SPARQL is defined.
> > >>>
> > >>>Classes, RDF, OWL, rules, etc. enter in as ways to infer new graphs
from
> > >>>given graphs (entailment). Shapes/constraints may apply to either
the raw
> > >>>graph or the inferred graph, depending in the application.
> > >>>_________________________________________________________
> > >>>Arthur Ryman
> > >>>Chief Data Officer
> > >>>SWG | Rational
> > >>>905.413.3077 (phone) | 416.939.5063 (cell)
> > >>>IBM InterConnect 2015
> > >>>
> > >>>
> > >>>
> > >>>
> > >>>From:   "Peter F. Patel-Schneider" <pfpschneider@gmail.com>
> > >>>To:     "Eric Prud'hommeaux" <eric@w3.org>,
> > >>>Cc:     Arthur Ryman/Toronto/IBM@IBMCA, public-data-shapes-wg@w3.org
> > >>>Date:   11/07/2014 09:23 AM
> > >>>Subject:        Re: Shapes, Individuals, and Classes - OSLC
Motivations
> > >>>
> > >>>
> > >>>
> > >>>OK, so then it's not just RDF graphs, it's something else.  What is
this
> > >>>else?
> > >>>
> > >>>peter
> > >>>
> > >>>
> > >>>On 11/07/2014 05:45 AM, Eric Prud'hommeaux wrote:
> > >>>>* Peter F. Patel-Schneider <pfpschneider@gmail.com> [2014-11-06
> > >>>20:36-0800]
> > >>>>>So your view is that all that counts is the graph?  Nothing about
> > >>>>>datatypes, or RDF, or RDFS?
> > >>>>
> > >>>>I suspect that OSLC wants datatypes, noting that Resource Shapes has
> > >>>>an oslc:valueType predicate for identifying the datatype of a
literal.
> > >>>>
> > >>>>
http://www.w3.org/Submission/2014/SUBM-shapes-20140211/#valueType
> > >>>>
> > >>>>
> > >>>>>peter
> > >>>>>
> > >>>>>
> > >>>>>On 11/06/2014 12:01 PM, Arthur Ryman wrote:
> > >>>>>>Peter,
> > >>>>>>
> > >>>>>>Commenting on your proposed wording of how to express the
"decoupling"
> > >>>>>>requirement. I'd go further and demote the notion of class to
being
> > >>>more
> > >>>>>>like just another property and view the shape/constraints as
applying
> > >>>to
> > >>>>>>the RDF representation of an information resource, i.e. to a set
of
> > >>>>>>triples (aka an RDF graph). Some of the triples will have
rdf:type as
> > >>>the
> > >>>>>>predicate and those triples are useful for locating certain
subject
> > >>>nodes
> > >>>>>>that we want to say more things about, e.g that they are the
subjects
> > >>>of
> > >>>>>>triples that have certain other predicates, etc.
> > >>>>>>_________________________________________________________
> > >>>>>>Arthur Ryman
> > >>>>>>Chief Data Officer
> > >>>>>>SWG | Rational
> > >>>>>>905.413.3077 (phone) | 416.939.5063 (cell)
> > >>>>>>IBM InterConnect 2015
> > >>>>>>
> > >>>>>>
> > >>>>>>
> > >>>>>>
> > >>>>>>From:   "Peter F. Patel-Schneider" <pfpschneider@gmail.com>
> > >>>>>>To:     Arthur Ryman/Toronto/IBM@IBMCA,
> > >>>>>>Cc:     public-data-shapes-wg@w3.org
> > >>>>>>Date:   11/06/2014 12:14 PM
> > >>>>>>Subject:        Re: Shapes, Individuals, and Classes - OSLC
> > >>>Motivations
> > >>>>>>
> > >>>>>>
> > >>>>>>
> > >>>>>>I still don't know what "custom" means here with respect to RDF.
As
> > >>>far
> > >>>>>>as I
> > >>>>>>can tell any bit of an ontology, or class, or property, or
constraint,
> > >>>or
> > >>>>>>shape could be called "custom".  Now it may be that within OSLC
there
> > >>>is
> > >>>>>>some
> > >>>>>>notion of custom vs non-custom, but how can that notion be removed
> > >>>from
> > >>>>>>OSLC
> > >>>>>>so that it can be used elsewhere?
> > >>>>>>
> > >>>>>>Similarly, the notions of "specification", "implementation",
> > >>>"project",
> > >>>>>>etc.,
> > >>>>>>appear to me to be specific to OSLC, and particular to the design
> > >>>>>>methodology
> > >>>>>>you outline below, and using them to drive a spec could, I think,
tie
> > >>>that
> > >>>>>>
> > >>>>>>spec quite closely to the design methodology.
> > >>>>>>
> > >>>>>>
> > >>>>>>
> > >>>>>>As a contrast, here is what I believe should be used to say that
> > >>>classes
> > >>>>>>and
> > >>>>>>shapes/constraints are decoupled.
> > >>>>>>
> > >>>>>>Definition:  Classes and shapes/constraints are decoupled if the
> > >>>>>>specification
> > >>>>>>can use different sets of shapes/constraints on the same class.
For
> > >>>>>>example,
> > >>>>>>if the specification permits the ontology
> > >>>>>>     ex:Person rdf:type rdfs:Class .
> > >>>>>>     ex:name rdf:type rdf:Property .
> > >>>>>>     ex:name rdfs:domain ex:Person .
> > >>>>>>to be used with the constraint set
> > >>>>>>     ex:Person < exists ex:name
> > >>>>>>(every person has a "known" value for its name)
> > >>>>>>or used with the constraint set
> > >>>>>>     ex:Person < all ex:name xsd:string
> > >>>>>>(all "known" names of people are strings)
> > >>>>>>then it will be said to allow the decoupling of
constraints/shapes and
> > >>>>>>classes.
> > >>>>>>
> > >>>>>>
> > >>>>>>A stronger notion would be that shapes/constraints are
independent of
> > >>>>>>classes.
> > >>>>>>    This could be defined as:
> > >>>>>>
> > >>>>>>Definition:  Classes and shapes/constraints are independent if
some
> > >>>>>>shapes/constraints do not use class membership in their
definition.
> > >>>For
> > >>>>>>example, the following constraint is class-independent:
> > >>>>>>     exists ex:name < exactly 1 ex:name
> > >>>>>>(if something has a "known" name then it has exactly one "known"
name)
> > >>>>>>
> > >>>>>>
> > >>>>>>peter
> > >>>>>>
> > >>>>>>
> > >>>>>>
> > >>>>>>
> > >>>>>>On 11/06/2014 04:59 AM, Arthur Ryman wrote:
> > >>>>>>>Peter,
> > >>>>>>>
> > >>>>>>>OSLC defines specification for RDF representation of resources in
> > >>>>>>several
> > >>>>>>>domains, e.g. Requirements, Quality, Change Management etc. A
> > >>>>>>>specification typically defines a class and several properties.
> > >>>>>>>Implementations are allowed to add new RDF properties but they
don't
> > >>>>>>>necessarily introduce new RDF classes. Furthermore, within an
> > >>>>>>>implementation, users may add custom RDF properties on a
> > >>>>>>>project-by-project basis, but that doesn't change the RDF class.
> > >>>>>>Therefore
> > >>>>>>>different projects use different Shapes but the Shapes only
differ by
> > >>>>>>RDF
> > >>>>>>>properties, not RDF classes. That is what I mean by decoupling
Shapes
> > >>>>>>and
> > >>>>>>>Classes.
> > >>>>>>>
> > >>>>>>>I will elaborate this on the wiki.
> > >>>>>>>_________________________________________________________
> > >>>>>>>Arthur Ryman
> > >>>>>>>Chief Data Officer
> > >>>>>>>SWG | Rational
> > >>>>>>>905.413.3077 (phone) | 416.939.5063 (cell)
> > >>>>>>>IBM InterConnect 2015
> > >>>>>>>
> > >>>>>>>
> > >>>>>>>
> > >>>>>>>
> > >>>>>>>From:   "Peter F. Patel-Schneider" <pfpschneider@gmail.com>
> > >>>>>>>To:     Arthur Ryman/Toronto/IBM@IBMCA,
public-data-shapes-wg@w3.org,
> > >>>>>>>Date:   11/05/2014 05:27 PM
> > >>>>>>>Subject:        Re: Shapes, Individuals, and Classes - OSLC
> > >>>Motivations
> > >>>>>>>
> > >>>>>>>
> > >>>>>>>
> > >>>>>>>I'm still wondering what you think it means to decouple shapes
and
> > >>>>>>>classes.
> > >>>>>>>The first motivation you provide is supported by both SPIN and
OWL
> > >>>>>>>constraints.  I can't figure out what custom properties have to
do
> > >>>with
> > >>>>>>>classes, or constraints, or shapes.  The behaviour you appear to
be
> > >>>>>>>looking
> > >>>>>>>for in your second paragraph is also supported by both SPIN and
OWL
> > >>>>>>>constraints.
> > >>>>>>>
> > >>>>>>>I had thought that this was ironed out at the Face-to-Face, but I
> > >>>guess
> > >>>>>>>not.
> > >>>>>>>
> > >>>>>>>peter
> > >>>>>>>
> > >>>>>>>
> > >>>>>>>On 11/05/2014 01:47 PM, Arthur Ryman wrote:
> > >>>>>>>>There are a few motivations for decoupling shapes and classes.
One
> > >>>is
> > >>>>>>>that
> > >>>>>>>>the creation shape may be different than the update shape.
Another
> > >>>has
> > >>>>>>>to
> > >>>>>>>>do with custom properties. I'll write up the following in the
wiki.
> > >>>>>>>>
> > >>>>>>>>OSLC supports an open content model for resources. It is common
for
> > >>>>>>>tools
> > >>>>>>>>to add their own custom properties, and for projects within a
tool
> > >>>to
> > >>>>>>>have
> > >>>>>>>>different user-defined properties. For example, consider a bug
> > >>>tracking
> > >>>>>>>>tool. Project A may add a custom property foo and project B may
add
> > >>>>>>bar.
> > >>>>>>>>All projects use the same RDF type for bug resources, e.g.
> > >>>>>>>>oslc_cm:ChangeRequest. However, the shape for resources in
project A
> > >>>>>>>>differs for the shape for project B.
> > >>>>>>>>_________________________________________________________
> > >>>>>>>>Arthur Ryman
> > >>>>>>>>Chief Data Officer
> > >>>>>>>>SWG | Rational
> > >>>>>>>>905.413.3077 (phone) | 416.939.5063 (cell)
> > >>>>>>>>IBM InterConnect 2015
> > >>>>>>>>
> > >>>>>>>>
> > >>>>>>>
> > >>>>>>>
> > >>>>>>>
> > >>>>>>
> > >>>>>>
> > >>>>>>
> > >>>>>
> > >>>>
> > >>>
> > >>>
> > >>>
> > >
>
> --
> -ericP
>
> office: +1.617.599.3509
> mobile: +33.6.80.80.35.59
>
> (eric@w3.org)
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