siks december 2008 law and the semanticweb

SIKS Course - Knowledge Modelling

Rinke Hoekstra

Law and the Semantic Web

10-12-2008

http://www.lri.jur.uva.nl/new/index.html



Overview

Why? Role of Artificial Intelligence Legal Sources

MetaLex Legal Knowledge Representation

OWL, LKIF

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WHY?

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Law is …

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Law is … rather peculiar It is illegal to die in the Houses of Parliament It is an act of treason to place a postage stamp bearing the

British king or queen’s image upside-down It is illegal for a woman to be topless in Liverpool except as

a clerk in a tropical fish store Eating mince pies on Christmas Day is banned If someone knocks on your door in Scotland and requires

the use of your toilet, you are required to let them enter In the UK a pregnant woman can legally relieve herself

anywhere she wants, including in a policeman’s helmet It is legal to murder a Scotsman within the ancient city

walls of York, but only if he is carrying a bow and arrow

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The Court

What happens in court? Dispute between two parties Dialectic Exchange of arguments Presenting a selection of the facts in a way

convenient to the case of a client. … is this about the truth?

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The Judge: Case Law

How does a judge come to a decision? Weighing the arguments Assessing and interpreting the facts

Legal interpretation Causal analysis

Comparing to similar cases Comparing to written law (legislation)

What is the effect of the decision? Precedent for new cases: Law is self-reflexive An actual change in the “real world”

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The Government: Legislation

Conflicting interests Every citizen should know the law

clarity, readability Every person and organisation should abide by the law

effectiveness, ability to uphold

Versus Political compromise

Intentionally cryptic and vague language Legal profession

Abstract, theoretical constructs, mystique

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Law is … ambiguous and imprecise

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Law is … inconsistent

Outcome of a case does not always follow ‘logically’ from premises Freedom of judge to decide

Internal inconsistencies Built-in conflict resolution

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Rule Type

Lex Specialis specificity

Lex Superior authority, jurisdiction

Lex Posterior temporal ordering



Law is ... tricky

Experts don’t want to be pinned down Not about truth Opaque Ambiguous and imprecise Inconsistent

… and there’s lots and lots of it

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Law is … relevant

Relevant Complex knowledge management issues Well structured, man made We’re all subject to it

European Union Multilingual Harmonisation

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ARTIFICIAL INTELLIGENCE?

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Two Perspectives

Epistemological Formal representation of legal theory

Status of facts as `legal’, creating legal knowledge Reasoning: case based reasoning, argument theory,

deontic logics, dispute resolution

Knowledge Representation Representation of law itself Annotation: versioning, authority, accessibility,

cross-referencing Reasoning: Assessment, planning, harmonisation,

simulation10-12-2008



… Different Requirements

Formal representation of legal theory Dialectic, defeasible, non-monotonic No real concern for tractability, completeness … any practical use?

Representation of the law itself Expert system perspective Tractability & completeness important Open world Traceability to sources

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… Sounds Familiar?

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Legal Layer Cake

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Layer Cake

Representation of structure of legal texts MetaLex XML

Lightweight annotation Resource Description Framework (RDF)

Representation of content Web Ontology Language (OWL) Legal Knowledge Interchange Format (LKIF)

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LEGAL SOURCES:METALEX

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MetaLex (A. Boer, R. Winkels, R. Hoekstra)

Interchange format Legal and legislative resources References between sources

Europe LexDania, Norme in Rete, chXML, etc.

Africa Akoma Ntoso (Fabio Vitali)

XML Schema CEN Workshop

http://www.metalex.eu10-12-2008

http://www.metalex.eu/



Schema Structure

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SIKS Course - Knowledge Modelling10-12-2008



Features

Exchange Common meaningful elements Identification (URI’s)

Presentation XHTML, PDF, …

Multiple Languages Version Management and Maintenance Extensibility Search and Filtering

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Versions

TextVersion elements Language

Locale dependent schema xml:lang tags

Time

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Attribute Meaning

date-version Text creation/modification date

date-published Publication date

date-enacted Date of enactment

date-effective Date start of effect

date-repealed Date end of effect



XSL

XSL

XSL



Extensibility Agnostic wrt. other XML standards

Search and Filtering Search at meaningful XML element level

Identification & Citation All elements have a URI Citation of parts of documents

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More semantics

Metadata as inline RDF References and Citations

RDFa attributes -> RDF triples

Transformation to RDF/OWL GRDDL

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LEGAL KNOWLEDGE REPRESENTATION

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Knowledge Types in Law

Modelling Perspective Legal Abstract Model

Breuker (1990) World Knowledge (Causal, Definitional) Normative Knowledge Responsibility Knowledge Meta-Legal Knowledge

Functional Ontology of LawValente (1995) Law as system that acts in and on society

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Functional Ontology of Law

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Incremental Approach

Core Ontology Bridges the gap between ‘common sense’

reality and the legal system Norms

Specify regulations that hold on reality

Norms ≠ Definitions Conflicting norms inconsistent reality?

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Bridging the Gap

LKIF Core Ontology (Hoekstra et al., 2008) Basic legal concepts

Shared by all legal domains Grounding in common sense

Roles Special legal inference Knowledge acquisition support Prevent loss in translation Semantic annotation

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Modules

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Main categories

Change Process Action

Physical Entity Objects

Mental Entity Subjective Entity

Abstract Entity Occurrence

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Step 2: Intentionality and Subjectivity

Intentional Stance (Dennett, 1987)

… Legal Stance

Construction of social reality (Searle, 1995) Constitutive rules (counts-as) Subjective entities

Roles, functions

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Roles

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Propositions, Attitudes and Expressions

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Representing Norms

Traceability (T. van Engers & Glassée, 2001) Connected to source

Isomorphic (T. Bench-Capon & Coenen, 1991) Structural correspondence

Annotation of Regulations Scoped representation parts, temporal validity, jurisdiction

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Representing Norms

Subjective entity Context: legal system

Three types: Permission Prohibition Obligation

Qualify a Situation (Generic Case) Allowed Disallowed

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Norms in LKIF Core

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Structural Correspondence

Legal Assessment (van de Ven et al., 2008)

Protégé OWL Judge plugin Tasks

Specify case Match against set of norms Conflict resolution

Standard DL reasoner (Pellet) + something extra

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Simple norms: University Library

1a) Students registered at this university are allowed to check out a book from this library

1b) Students registered at other universities are allowed to check out a book from this library provided that they are enrolled in at least one course given at this university.

1c) Students who have checked out more than five books are not allowed to check out another book.

Lex specialis hierarchy:

Art1c ⊑ Art1a, Art1c ⊑ Art1b

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Default Norm

0) Default: Checking out books is disallowed.

Default_GC⊑ Generic_Case⊑ ∃disallowed_by.{defaultnorm}≡ ∃checks_out.Library_Book

Default_Norm

⊑ Prohibition ⊑ ∀disallows.Default_GC≡ {defaultnorm}

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Article 1a

1a) Students registered at this university are allowed to check out a book from this library.

Art1a_GC⊑ Generic_Case⊑ ∃allowed_by.art1a≡ Registered_Student ⊓

∃checks_out.Library_Book Art1a_Permission

⊑ Permission⊑ ∀allows.Art1a_GC≡ {art1a}

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Article 1c1c) Students who have checked out more than five books are not

allowed to check out another book.

Art1c_GC_F⊑ Generic_Case⊑ ∃disallowed_by.{art1c}≡ Registered_Student ⊓ ≥ 6 checks_out.Library_Book

Art1c_GC_P⊑ Generic_Case⊑ ∃allowed_by.{art1c}≡ Registered_Student ⊓

∃checks_out.Library_Book≤ 5 checks_out.Library_Book

Art1c_Prohibition ⊑ Prohibition⊑ ∀disallows.Art1c_GC_F ⊓ ∀allows.Art1c_GC_P ≡ {art1c}10-12-2008



Conflict Resolution

AmyC {Amy :Student, book_1 :Library_Book, … , book_6 :Library_Book, Amy checks_out book_1, … , Amy checks_out book_6} Matches

Default_GC, Art1a_GC, Art1c_GC_F … corresponding norms

Most specific GC Art1c_GC_F

Outcome Art1c_Prohibition: disallowed

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Temporal Validity

Versions and Applicability of Concept Definitions (Klarman, Hoekstra, Bron, 2008)

How to deal with versions? Different classification of domain objects Reasoning results in different outcome Impact may be significant

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Temporal Validity (1)

Definitions hold independently, at the same time Complex determination of validity of

definitions Applicability & Activity

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Immediate

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Retroactive

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Delayed

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Requirements

General purpose representation formalism Incremental versioning

New version of a concept should have minimal impact

Co-existence of multiple (incompatible) versions Ability to switch between versions Reasoning on both versioned and version-

independent concepts Validity depends on multiple intervals

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Representation

A dynamic concept is a concept whose meaning changes over time

Each new concept variant is introduced as a defined class, subsumed by the dynamic concept class.

Concept variants are valid within some combination of intervals.

A DL reasoner classifies individuals as class members, based on the choice of a current interval.

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GeneralTRestriction

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Dynamic Concept

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Jurisdiction

Legal Atlas Spatial Plans

Which activities are allowed where?

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THE END

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siks december 2008 law and the semanticweb

Education

law legislationwhat

legal knowledgereasoning

legal layer cake10

case lawhow

premisesfreedom of judge

crossreferencing reasoning

real world

xml standardssearch