1 Jérôme Euzenat 655 avenue de lEurope, Montbonnot Saint-Martin, France Interoperability in an open semantic web (was: semantically grounded transformation)

2 Outline Why the semantic web must be open… Why the semantic web must be safe… …research needed.

3 Semantic web

4 Semantic webs

5 Heterogeneity Language suitability (expressiveness…) Preferences Legacy knowledge Techno-diversity is good! Are the languages really mature?

6 Dealing with heterogeneity Addressing; Transforming; Trusting; Acknowledging; …as infrastructure services of the semantic web.

7 Semantic failure Current web Semantic web !? core dumped 404

8 Semantic failure (2) Current web Semantic web !?

9 Semantic failure (3) Current web Semantic web !?

10 Safety threats Interoperability problems can come from: language heterogeneity; model incompatibility (in modelling). We must provide tools for dealing with these…as far as possible.

11 L Property satisfaction T( ) L T, T( ) L T( ) => L, L => T( ) L T( )

12 Predicate expanding transformations [Masolo]: can replace predicate symbols by arbitrary formulas. Equivalent to articulation axioms/interpretations. ( ) FOL, FOL => ( ) FOL ( )

13 Generally applicable scheme Even when just some data is exported from one database; Even when the languages are not the same; Even when the ontologies are not the same. Not applicable when nothing has to be transformed.

14 Transforming One can be built from scratch… Printer support Tech support Printers No transformation being available,

15 Composing transformations daml 2dlml oil 2dlml domain 2invall oneof 2cexcl cexcl 2not Printer support Tech support Printers

16 Gathering transformations daml 2dlml oil 2dlml domain 2invall oneof 2cexcl cexcl 2not domain 2invall Printer support Tech support Printers

17 Transforming with properties T L: Printer support L: Tech support Printers, L => T( ) L T( ) Preserving consequences

18 Gathering properties about daml 2dlml oil 2dlml domain 2invall oneof 2cexcl cexcl 2not domain 2invall < Printer support Tech support Printers

19 Proof-carrying transformations about daml 2dlml oil 2dlml domain 2invall oneof 2cexcl cexcl 2not domain 2invall < Printer support Tech support Printers

20 Exporting transformation and property T

21 Safe transformation development cycle Fetching transformations; Fetching assertions and proofs; Checking the proofs (or trusting the assertions); Composing transformations; Proving that the composition satisfies the required properties; Publishing transformation and properties.

22 Technologies < RDF OMDoc XSLT/Transmorpher

23 Research needed: theory Proving properties of transformations; Logic: interpretation of theories, higher-order; Language manipulation and adapting; Proof, properties and semantics expression languages;

24 Research needed: practice Development of proof checkers; Integration in the semantic web; Infrastructure for trust and proof; Trade-off: how good is good enough?

25 Summary The semantic web needs research for: an infrastructure supporting heterogeneity declined along: addressing, transforming, trusting, acknowledging… a mechanical way to support property- enforcement when gathering knowledge: consistency, meaning-preservation, order- preservation…

26 And… I would like to see this implemented within the basic infrastructure. We have got PGP for years and no one is using it and the INRIA is resisting to have wireless networks because it is not safe! => a cause of failure, not unavoidable.