OWLDiff

A tool to perform a 2-way diff of OWL ontologies.

Requirements

• Java 14

Features

• syntactic diff/merge functionality
• explanations for inferred axioms
• various visualization options - Manchester/DL syntax, classified view, plain axiom list
• fully semantic diff for EL using the CEX algorithm.
• easy Subversion integration

PLAIN (SYNTACTIC) DIFF

• is provides an axiom by axiom difference of the ontologies
• different axioms are shown in ‘green’, the common parts are blue (and hidden by default).

ENTAILMENT CHECK

• for each axiom that is not contained in the other ontology an entailment check tests whether it can be derived from the other ontology or not.
• entailed axioms are shown in ‘red’
• for inconsistent ontologies the entailment check is disabled

CEX DIFF

• if either of the ontologies is not EL, no CEX is performed
• axioms with colored background denote those that appear either in DiffR or DiffL list - they represent semantic differences between the classes the semantics of whose has changed

  (as described in http://www.webont.org/owled/2008dc/papers/owled2008dc_paper_12.pdf)

ENTAILMENT EXPLANATIONS

• the incremental algorithm for single explanation generation is used (as described in Křemen, P. - Kouba, Z.: Incremental Approach to Error Explanations in Ontologies. In Proceedings of I-KNOW `07. Graz: Graz University of Technology, 2007, p. 332-339. ISSN 0948-695X )

Known Limitations

• imports are currently NOT resolved
• just one explanation generated for a single axiom - TODO provide the possibility to get all explanations
• usually the only sensible use is to compare ontologies with the same URI - no check is performed to find out whether the ontology/class/property/individual URI changed.

How to run it?

• to show the GUI without setting the input files in advance run

        'java -jar owldiff.jar' (or the convenience script 'owldiff' on linux)

• to perform the diff of file/URI and file/URI run

        'java -jar owldiff.jar <u1> <u2>' (or the convenience script 'owldiff <u1> <u2>' on linux)

2020 Czech Technical University, Knowledge Based and Software Systems Group