we have an ontology which was originally created manually as an rdf
schema and is now being updated using Protege, and the problem is that
blank nodes in a property are duplicated each time the ontology is
saved. This means that the ontology grows exponentially in size. I
created a simplified rdf schema (below) for reproducing the issue. We
use Protege 4.3 on Windows 7, but I can reproduce the issue with older
versions of Protege too.
1. Paste the rdf schema into a file
2. Open the file with Protege
3. Save the file as RDF/XML using "Save as" (at this point the property
is transformed into an annotation property and an object property, which
isn't a problem)
4. Open the saved file and save again as RDF/XML using "Save as"
The resulting ontology contains duplicate ex:annotation -properties
which contains the blank node. This doesn't happen if the resource is
named. Any ideas how to solve this?