Presentation is loading. Please wait.

Presentation is loading. Please wait.

1 W3C Rules Interchange Format Basic Logic Dialect Chris Welty IBM Research & RIF WG co-Chair.

Similar presentations


Presentation on theme: "1 W3C Rules Interchange Format Basic Logic Dialect Chris Welty IBM Research & RIF WG co-Chair."— Presentation transcript:

1 1 W3C Rules Interchange Format Basic Logic Dialect Chris Welty IBM Research & RIF WG co-Chair

2 2 Rules, rules, rules…

3 3 The Web Standards

4 4 Semantic Web Layer Cake V 1

5 5 Semantic Web Layer Cake V past IRI/Unicode RDF RDFS OWL Rules Logic Proof Trust Signature

6 6 Semantic Web Layer Cake V present IRI/Unicode RDF RDFS Rules Logic Framework Trust Encryption Proof OWL SPARQL Signature Standards Rules RDFS Rules

7 7 RIF Background Semantic web approach –interoperability requires a formal semantics The OWL WG approach –Start with something (DAML+OIL) Literally hundreds of rule system implementations –JSR-94, ISO-Prolog, CLIPS, OPS… –http://www.w3.org/2005/rules/wg/wiki/List_of_Rule_Systemshttp://www.w3.org/2005/rules/wg/wiki/List_of_Rule_Systems –Already several SW rule languages SWRL, RuleML, WRL, SWSL, KAON2, TRIPLE, JenaRules… –Everyone wants their system/technique/theory to be the SW rule standard Workshop April 05 –http://www.w3.org/2004/12/rules-ws/http://www.w3.org/2004/12/rules-ws/ –Outcome: Nash Equilibrium…

8 8 Wherefore the RIFt(s)? OWL DL < OWL < FOL –Original idea to add full first-order at the logic level –Semantic web very open world Most back-end DBs support closed queries Many rule systems have non-FO features –CWA/NAF –Procedural Attachment –Rule ordering –Non-monotonicity … cant be layered on OWL Not a strict SW layering already –OWL restricted dialects (DL) not layered on (all of) RDF/S semantics –RDF & RDFS not layered at all

9 9 Enter the Vendors Rule systems Vendors –$1B/year existing market –iLog, Fair Isaac, Haley, … Database vendors –Oracle, IBM OMG PRR effort –Simple production rules –Event-condition-action –Vendors understand the value of standardization –Interchange already a priority –…a common semantics?

10 10 One must understand, [rule systems] include a version of negation that is operationally well-defined. The problem is to make semantic sense of it. Fitting, 1999

11 11 Approach 1 Define a super-language so expressive that any language can be translated to/from it –The CL and IKL infeasible for this group, as major differences appeared irreconcilable (e.g. non-mon vs. mon)

12 12 Approach 2 Define a core language that accounts for the intersection of all rule language capabilities –E.g. Horn, datalog, The production rule, logic programming, and FO core is not clear

13 13 Approach 3 Define a logic-based core and a separate production-rule core. If there is an intersection, define the common core (which may possibly be just a 0.1 BLD

14 14 Approach 3a Define a framework in the form of a menu of syntactic and semantic features that can be combined into dialects (FLD)

15 15 Credits BLD Editors –Michael Kifer (U. Stonybrook), Harold Boley (NRCC) Active WG members –Adrian Paschke (REWERSE), Axel Polleres (DERI), Dave Reynolds (HP), Gary Hallmark (ORACLE), Hassan Aït-Kaci (ILOG), Igor Mozetic (JFI), John Hall (OMG), Jos de Bruijn (FUB), Leora Morgenstern (IBM), Mike Dean (SRI), and Stella Mitchell (IBM) WG Team –Chris Welty (IBM), Christian de Sainte Marie (ILOG), and Sandro Hawke (W3C/MIT)

16 16 BLD Overview Definite Horn rules –Disjunction of atoms with exactly one positive literal Equality, functions, and a standard first-order semantics Syntactic features –objects and frames –internationalized resource identifiers (IRIs) as identifiers –XML Schema data types and builtins XML (1.0) syntax with normative XMLS definition Non-normative presentation syntax Metadata and imports

17 17 Symbols Used to identify constants, variables, functions, predicates "literal"^^ –Notable symbol spaces: xsd:string, rif:local, rif:iri –Chris^^ –http://www.w3.org/1999/02/22-rdf-syntax- ns#type^^ ns#type^^

18 18 Rules IF THEN – aka rule body, antecedant – aka rule head, consquent BLD rule: –(Forall var* :- ) –Conclusions may contain conjunction –Conditions may contain conjunction, disjunction, and existential Restrictions on conclusion –No existential, disjunction, external functions

19 19 Horn Extensions Functions and external calls Equality (in conclusion and condition) Frames –Objects with slots and values –Special syntactic treatment of type and subclass Named argument functions and predicates –However all arguments must be provided

20 20 Structure Rules occur in Groups Group((Forall ?x _Q(?x) :- _P(?x)) (Forall ?x _Q(?x) :- _R(?x)) ) Groups occur in Documents Document( Group((Forall ?x _Q(?x) :- _P(?x)) (Forall ?x _Q(?x) :- _R(?x))) Group((Forall ?y _R(?y) :- ex:op(?y))))

21 21 Simple Example Database mapping Document( Prefix(dbp Prefix(my Prefix(rdfs Group ( Forall ?mname ?aname ?movie ?actor my:actorIn(?aname ?mname) :- And( dbp:starring(?movie ?actor) rdfs:label(?movie ?mname) rdfs:label(?actor ?aname))))

22 22 Document( Prefix(dbp Prefix(my Prefix(rdfs Group ( Forall ?mname ?aname ?movie ?actor my:actorIn(?aname ?mname) :- And(?movie[dbp:starring -> ?actor rdfs:label -> ?mname] ?actor[rdfs:label ?aname]))) Simple Example w/ Frames Database mapping

23 23 Document( Prefix(dbp Prefix(my Prefix(rdfs Group ( Forall ?mname ?aname ?movie ?actor my:actorIn(actor->?aname movie->?mname) :- And(?movie[dbp:starring -> ?actor rdfs:label -> ?mname] ?actor[rdfs:lasbel ?aname]))) Named Arguments

24 24 And (Exists ?Buyer (cpt:purchase(?Buyer ?Seller cpt:book(?Author bks:LeRif) curr:USD(49))) ?Seller=?Author ) Buyer &cpt;purchase Buyer Seller &cpt;book Author &bks;LeRif &curr;USD 49 Seller Author XML Syntax

25 25 Metadata Can hang off any class element pd &dc;publisher &w3;W3C...

26 26 Metadata Can hang off any class element pd &dc;publisher &w3;W3C...

27 27 Metadata Can hang off any class element pd &dc;publisher &w3;W3C...

28 28 Status RIF BLD to Last Call June 23 RIF RDF&OWL to Last Call June 23 Last call indicates final version for external review w3.org/2005/rules


Download ppt "1 W3C Rules Interchange Format Basic Logic Dialect Chris Welty IBM Research & RIF WG co-Chair."

Similar presentations


Ads by Google