Representing the Differences Between two Models from Arnold deVos on 2001-03-28 (www-rdf-interest@w3.org from March 2001) (original) (raw)

Here is a proposal [1] for representing the difference between two RDF models as an RDF model. In the electric power industry have a use case for this in exchanging power system models between utilities [2]. I would imagine there are others who have giant models like us and sometimes need to handle only the differences.

Something like this requires quoting of RDF statements. I know this is supposed to be covered by rdf:bagID, but I couldn't see how to use that in this case without creating a self-contradictory model. Therefore I am floating an (application-specific?) extension to the syntax, parseType="Statements". This is supposed to be similar to the braces in N3 [3].

Here is an illustration of a difference model using this extension:

<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:cim="http://iec.ch/TC57/2000/CIM-schema-cimu09a#" xmlns:dm=http://iec.ch/TC57/2001/Differences> <rdf:Description about=""> <dm:preconditions parseType="Statements"> <dm:forwardDifferences parseType="Statements"> <dm:reverseDifferences parseType="Statements">

Here is a short definition of the parseType used above:

• The content model of a property element with rdf:parseType="Statements" is the same as the content model of the rdf:RDF element.

• The content generates the same RDF statements as if it appeared in an rdf:RDF element. Note: these statements may duplicate or contradict others outside the enclosing element. RDF processors are not entitled to eliminate such duplicates. The statements are in a separate "context".

• The value of a property element with rdf:parseType="Statements" is a collection of resources of type rdf:Statement, representing the generated statements.

• Arnold

[1] http://www.langdale.com.au/CIMXML/DifferenceModelsR03.pdf (Sorry only in PDF for the moment.)

[2] http://www.langdale.com.au/CIMXML

[3] http://www.w3.org/DesignIssues/Notation3.html

Received on Wednesday, 28 March 2001 04:20:25 UTC