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Re: PROV comments from Clark&Parsia

From: Evren Sirin <evren@clarkparsia.com>
Date: Mon, 7 Jan 2013 15:29:35 -0500
Message-ID: <CAFC3-Qq+M66E8HGJg8OBN1AcpLrS8ETbK_w08QTNJKszQYTqkw@mail.gmail.com>
To: Paul Groth <p.t.groth@vu.nl>
Cc: "public-prov-comments@w3.org" <public-prov-comments@w3.org>
Thanks Paul.

This is a minor point but there was one obvious copy/paste error in
the OWL encoding examples we sent. The last example should have been:

# Inference 20 (specialization-alternate-inference)
# IF specializationOf(e1,e2) THEN alternateOf(e1,e2).

:specializationOf rdfs:subPropertyOf :alternateOf .

And this axiom is actually included in the current PROV-O ontology so
it is kind of irrelevant for the point we were making.

Best,
Evren

On Sun, Jan 6, 2013 at 1:51 PM, Paul Groth <p.t.groth@vu.nl> wrote:
> 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
Received on Monday, 7 January 2013 20:30:22 GMT

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