Hi Mario,

Thanks so much for reviewing these documents. This sort of feedback
is very helpful.

On Fri, May 13, 2011 at 6:45 AM, Mario Tokarz <mario@...> wrote:

I am just reading into the SPDX sample you offered for download. I
have two questions (I read the sample in connection with SPDX Version
Draft 20110411).

It might also be useful to look at <http://spdx.org/rdf/terms>. This
is the formal OWL ontology for SPDX. This information is being
integrated into the spec at this time. The complete spec will be
available shortly.

1. In http://spdx.org/rdf/terms#Package there are references to
licenses in the fields 'licenseInfoFromFiles' and
'licenseCondluded'. Both are defined with Cardinality 1..*. However
they differ in the implementation: licenseInfoFromFiles references
directly either known-liceneses as rdf:resource or
rdf:node. licenseCondluded refers to a ConjunctiveLicenseSet with
members referring to rdf:resource or rdf:node.  Could you please
evaluate on this difference? There does not seem to be a formal
definition for the ConjunctiveLicenseSet.

A formal definition of ConjunctiveLicenseSet is in the
<http://spdx.org/rdf/terms> document.

`licenseInfoFromFiles` and `licenseInfoInFiles` are simple inventories
of the licensing related text found in a package or file,
respectively. The declared and concluded license fields provide a way
for the producer of an SPDX file to state the actual and complete
licensing regime of an item.

For example, a package might allow copiers to choose between two
licenses because it is dual licensed, or might require copiers to
comply with two licenses because it contains some content under each
license. The `licenseInfoFromFiles` properties would be
indistinguishable in those two cases. (Both licenses would be
listed.) The declared and concluded licenses would be quite
different. In the choose between two licenses scenario it would be a
DisjunctiveLicenseSet and in the second scenario it would be a
ConjunctiveLicenseSet.

2. The artifactOf field refers to a node which is defined as
http://usefulinc.com/ns/doap#Project. This seems a bit broken to me,
because the element is not declared as an SPDX internal type.  On a
syntax level your example contains

<rdf:Description rdf:nodeID="A12">
   <j.0:homepage>http://www.openjena.org/</j.0:homepage>
   <j.0:name>Jena</j.0:name>
   <rdf:type rdf:resource="http://usefulinc.com/ns/doap#Project"/>
 </rdf:Description>

I would have expected somthing like this:
 <rdf:Description rdf:nodeID="A12">
   <homepage>http://www.openjena.org/</homepage>
   <name>Jena</name>
   <rdf:type rdf:resource="http://spdx.org/rdf/terms#ArtifactOf"/>
 </rdf:Description>

I think the RDF in Gary's example is correct. The homepage and name
properties are in the DOAP namespace. We utilize the existing
definitions of project homepage and name, rather than creating our own
very similar properties. (No need to reinvent the wheel.) The SPDX
ontology imports the DOAP schema so those properties and class are
available directly.

Hope these explanations clarify these issues. Any suggestions as to
how the documentation might be modified to clarify these issues are
very welcome.

Peter
openlogic.com