Re: PROV comments from Clark&Parsia

Dear Evren,

First, thanks for deciding to implement PROV. Obviously, we need to discuss
and get back to you about how the group thinks it can best address your
comments.

In the meantime, I've created an issue to track the discussion.

https://www.w3.org/2011/prov/track/issues/611

We'll get back to you asap.

Thanks again,
Paul

P.S. Tracker this is ISSUE-611



On Fri, Jan 4, 2013 at 6:23 PM, Evren Sirin <evren@clarkparsia.com> wrote:

> Hi all,
>
> We are working towards supporting PROV inferences and constraints in
> our RDF database Stardog [1]. Below are some comments about PROV
> specification documents that we identified while working on our
> implementation.
>
> * PROV Constraints
>
> 1. The flow control arrows in Figure 1 seem to be backwards.
> 2. Definition 2.1 seems to be missing the id on the right-hand side.
> 3. Since uniqueness constraints are ‘applied’ and can derive new
> atoms, it is misleading to call them constraints. The same applies to
> typing constraints.
> 4. The definition of enforcement of uniqueness constraints states one
> should apply the resulting substitution to the whole PROV instance.
> However, the scope of the variables is not sets of rules.
> 5. Inference 9 (wasStartedBy-inference) should be: IF
> wasStartedBy(_id; _a,e1,a1,_t,_attrs), THEN there exist _gen and _t1
> such that wasGeneratedBy(_gen; e1,a1,_t1,[]).
> 6. Inference 10 (wasEndedBy-inference) should be: IF wasEndedBy(_id;
> _a,e1,a1,_t,_attrs), THEN there exist _gen and _t1 such that
> wasGeneratedBy(_gen; e1,a1,_t1,[]).
> 7. Inference 15.4 should be: IF wasStartedBy(id; a2,e,_a1,_t,attrs)
> THEN wasInfluencedBy(id; a2, e, attrs).
> 8. Inference 15.7 should be: IF wasDerivedFrom(id; e2, e1, _a, _g, _u,
> attrs) THEN wasInfluencedBy(id; e2, e1, attrs).
> 9. Constraint 56 should be: IF hadMember(c,e) and
> 'prov:EmptyCollection' ∈ typeOf(c) THEN INVALID.
>
> * PROV-O
>
> PROV Ontology contains several axioms for inferencing but it does not
> cover all the inferences described in the PROV constraints document
> even though these inferences can be encoded in OWL in a
> straightforward way. We think these inferences are useful not just for
> validation but also for querying PROV documents. For this reason, we
> believe these inferences should be included in PROV-O.
>
> Here are some example OWL axioms encoding some of the inferences from
> PROV constraints document:
>
> # Inference 16 (alternate-reflexive)
> # IF entity(e) THEN alternateOf(e,e).
>
> :Entity
>    rdfs:subClassOf [
>        a owl:Restriction ;
>        owl:hasSelf true ;
>        owl:onProperty :alternateOf
>    ] .
>
> # Inference 17 (alternate-transitive)
> # IF alternateOf(e1,e2) and alternateOf(e2,e3) THEN alternateOf(e1,e3).
>
> :alternateOf a owl:TransitiveProperty .
>
> # Inference 18 (alternate-symmetric)
> # IF alternateOf(e1,e2) THEN alternateOf(e2,e1).
>
> :alternateOf a owl:SymmetricProperty .
>
> # Inference 19 (specialization-transitive)
> # IF specializationOf(e1,e2) and specializationOf(e2,e3) THEN
> specializationOf(e1,e3).
>
> :specializationOf a owl:TransitiveProperty .
>
> # Inference 20 (specialization-alternate-inference)
> # IF specializationOf(e1,e2) THEN alternateOf(e1,e2).
>
> :specializationOf rdfs:subPropertyOf owl:TransitiveProperty .
>
> * PROV-CONSTRAINTS Test Cases
>
> We appreciate as implementers the PROV-Constraints test suite. We
> would like to see test suites for the other operational parts of PROV,
> in particular for testing inferences separate from validation. This
> request arises from our general belief that interoperability with a
> formal spec is typically less high than interoperability with a formal
> spec *and* an executable test suite. Test suites are invaluable for
> implementations. Further, while we would like to see the test suites
> be made normative parts of PROV (since that gives a nice algorithm for
> resolving disagreements between spec test and test suite (i.e., tie
> goes to the test suite)), we would prefer non-normative test suites to
> no test suites at all.
>
> We identified the following issues in the following RDF test cases:
>
> * prov-o-class-Invalidation-PASS.ttl: At line 37, there are repeated
> semi-colons ‘;;’ which is invalid according to the Turtle grammar
> (neither [2] nor [3] seems to allow this).
> * prov-o-class-Collection-PASS.ttl: Invalid xsd:dateTime literals
> missing minutes and timezone identifier.
> * prov-o-property-hadMember-PASS.ttl: Invalid xsd:dateTime literals
> missing minutes and timezone identifier.
> * ordering-association2-PASS-c47.ttl: This test is marked PASS but it
> is inconsistent because the individual ex:ag is an instance of
> disjoint classes prov:Entity and prov:Activity.
> * prov-o-property-qualifiedCommunication-PASS.ttl: This test is marked
> PASS but it is inconsistent because the individual
> :writing-celebrity-gossip is an instance of prov:Activity but uses the
> property prov:wasAttributedTo whose domain is the disjoint class
> prov:Entity. Same argument is also true for the individual
> :voicemail-interception.
> * prov-o-property-qualifiedRevision-PASS.ttl: This test is marked PASS
> but it is inconsistent because the individual :draft2 is an instance
> of prov:Entity but uses the property prov:wasAssociatedWith whose
> domain is the disjoint class prov:Activity.
>
> We think following tests should not have been included in
> rdf-tests.txt because the invalid PROV-N constructs cannot be
> expressed in RDF and thus their RDF representation is valid:
>            unification-association-f4-FAIL-c23.ttl
>            unification-association-f5-FAIL-c23.ttl
>            unification-derivation-f1-FAIL-c23.ttl
>            unification-derivation-f2-FAIL-c23.ttl
>            unification-derivation-f3-FAIL-c23.ttl
>            unification-derivation-f4-FAIL-c23.ttl
>
> Best,
> Evren
>
> [1] http://stardog.com/
> [2] http://www.w3.org/TeamSubmission/turtle/#sec-grammar
> [3] http://www.w3.org/TR/turtle/#sec-grammar
>
>
> --
> Evren Sirin
> CTO
> Clark & Parsia, LLC
> http://clarkparsia.org
>
>


-- 
--
Dr. Paul Groth (p.t.groth@vu.nl)
http://www.few.vu.nl/~pgroth/
Assistant Professor
- Knowledge Representation & Reasoning Group |
  Artificial Intelligence Section | Department of Computer Science
- The Network Institute
VU University Amsterdam