Jérôme Euzenat 655 avenue de l’Europe, Montbonnot Saint-Martin, France Enabling technologies for semantic interoperability

semanticThe web

The semantic webs

Query Conceptual graphs Description logics Object-based KR language Escrire (INRIA) (with Orpailleur and Acacia projects)

Reasons for heterogeneity Language suitability (expressiveness…) Preferences Legacy knowledge Techno-diversity is good! Are the languages really mature? Some reasons are arguable but some are good

Knowledge (ontology) representation language Ontology Language reasonner semantics Description

Levels of understanding —syntactic =XML and various schemas; —lexical (term used) =shared ontologies and transformations; —semantic (language meaning) =model theory; —semiotic/pragmatic (interpretation modes) =semiotic account.

Meaning preservation  T()T() KRL1 KRL , T(  )|= KRL T(  )   |= KRL1  ,  |= KRL1   T(  ) |= KRL T(  ) T

Solutions Pivot languages Modular family of languages Transformation and properties Pattern-based language construction

Pivot language In the line of the Web: the HTML of knowledge Which one? Not problem free: loss of knowledge, confusion… (no round trip).

Problems of Pivot Confusion! OK? Loss of knowledge OK KRL1 Pivot KRL2 KRL1 Pivot KRL2 KRL1 Pivot KRL2KRL1 Pivot KRL2

The modular semantic way L1L1 r1r1 s1s1 LnLn rnrn snsn L=ƒ l (L 1,…L n ) r=ƒ r (r 1,…r n ) s =ƒ s (s 1,…s n ) This have been done in DLML for syntax and semantics and mainly in description logics for reasonners Elementary operators

DLML: features Modular conception of DL descriptions: Description ( DTD, DSD ) of 40+ constructors Automatic generation of 25+ logics by assembling constructors Compatible DTD for all logics. Note: inference rules could be described the same way.

DLML: transformations From logic specification to DTD and DSD From logic to LaTeX From ALC to ALUE From ALC to AL From FaCT to ALUNI and back From Syllogistic to AL and back

The semantic-driven transformation L1L1 LpLp L r1r1 s1s1 rprp spsp T p = ƒ t (L p,s p /L,s) r s T 1 = ƒ t (L 1,s 1 /L,s)

L1L1 LpLp L r1r1 s1s1 rprp spsp T p = ƒ t (L p,s p /L,s) r s T 1 = ƒ t (L 1,s 1 /L,s) The semantic-driven transformation ont 1 ont p Ont = T 1 (ont 1 )+ T p (ont p ) This is easily doable when L i  L but can become really hard

DSD: principles Coded by using MathML and Xpath conventions Require the interpretation of the language.

DSD: example … …

DSD: constructs declare-domain : declare a particular set that can be referred to later (using domain ); interpretation-domain : specifies the range of interpretation of a particular constructor; denotation : specifies the denotation of a constructor (referred by apply-interpretation ); satisfaction : specifies the satisfaction condition of an assertion.

DSD: purpose pretty-printing semantics (XSLT); documenting a format; computing base interpretation (XSLT); proof-checking transformations; assisted proof (properties of transformations); automatic proof (p.o.t.); …

The ontology-pattern way (with Heiner Stuckenschmidt, TZI-Bremen) L1L1 r1r1 s1s1 LnLn rnrn snsn L=ƒ l (L 1,…L n ) r =ƒ r (r 1,…r n ) s =ƒ s (s 1,…s n ) ƒ r (.) ƒ s (.) ƒ l (.)

DLML as a pattern? ƒ s (.)=the interpretation of a term is still the intersection of the interpretation of the constructors ƒ l (.)=the entry for roles must accept the constructor with its own syntax Adding a role constructor This is still part of the easy things to do …because DL have been neatly designed

The pattern-based transformation ont 1 ont p  ’’  ’  -1 ƒ(  ’  -1 )

Conclusion The interoperability issue is a serious problem at the web-scale. There are many useful, doable, reasonable techniques (e.g. DLML); The general case is difficult

Conclusion There are many useful, doable, reasonable examples (e.g. DLML); The general case is difficult => Promising research topic.

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