a model-based approach to the automatic revision of ... · 2 modelling of legal speci cation formal...

A Model-based Approach to the Automatic Revision ofSecondary Legislation

Tingting Li1 Tina Balke2,1 Marina De Vos1 Julian Padget1

Ken Satoh3

1University of Bath{t.li,mdv,jap}@cs.bath.ac.uk

2University of [email protected]

3National Institute of [email protected]

The 14th International Conference on AI and Law (ICAIL 2013)

Li et al. (ICAIL 2013) Automatic Revision June 12, 2013 1 / 17

Motivation

1 Motivation

2 Modelling of Legal Specification

3 Automatic Conflict Detection

4 Conflict Resolution via Automatic Revision

5 Future Work

Motivation

Conflict of Laws

Law is dynamic: adding new laws or amending existing ones.

Existing inferior law (or set of regulations) may no longer beconsistent with the new superior law: an action permitted(obliged) inone but prohibited in another.

possibly resulting in (unintended) illegal behaviour.

Problem: detection and resolution of such conflicts automatically.

In particular: Will a specific scenario (a course of actions) result in aconflict? How to revise existing laws to remove this conflict?

Motivation

Conflict of Laws

Law is dynamic: adding new laws or amending existing ones.

Existing inferior law (or set of regulations) may no longer beconsistent with the new superior law: an action permitted(obliged) inone but prohibited in another.

possibly resulting in (unintended) illegal behaviour.

Problem: detection and resolution of such conflicts automatically.

In particular: Will a specific scenario (a course of actions) result in aconflict? How to revise existing laws to remove this conflict?

Motivation

Case Study

Recent change in UK immigration law about student visa regulation 1.

UK Immigration Law : the permitted working hours of overseasstudents are reduced: up to 20 hours per week.

Studentship Regulations: minimum number of teaching hours thestudent has to deliver: at least 30 hours per week.

1Detailed changes can be found on the UK Home Office website under http://www.ukba.homeoffice.gov.uk/sitecontent/documents/news/sop4.pdf.

Motivation

Case Study

Recent change in UK immigration law about student visa regulation 1.

UK Immigration Law : the permitted working hours of overseasstudents are reduced: up to 20 hours per week.

Studentship Regulations: minimum number of teaching hours thestudent has to deliver: at least 30 hours per week.

1Detailed changes can be found on the UK Home Office website under http://www.ukba.homeoffice.gov.uk/sitecontent/documents/news/sop4.pdf.

Modelling of Legal Specification

1 Motivation

2 Modelling of Legal SpecificationFormal Model SketchMapping to AnsProlog

5 Future Work

Modelling of Legal Specification Formal Model Sketch

Model sketch

World Model

ObsEv1 ObsEv2 ObsEv3 ObsEv4

Legal Specification

fluent1

fluent ′1fluent ′2fluent ′3

act1 fluent ′′1fluent ′′3

Model generates ordered traces that show us the evolution of thelegal specification over time—allows validation and verification.

Essential elements of model are:events (E): exogenous and legalfluents (F): power, permission, obligation, domain

Legal Specification: L := 〈E ,F ,G, C,∆〉

Model sketch

World Model

Legal Specification

fluent1

Model sketch

World Model

Legal Specification

fluent1

Model sketch

World Model

Legal Specification

fluent1

Model sketch

World Model

Legal Specification

fluent1

Modelling of Legal Specification Mapping to AnsProlog

Framework translation to AnsProlog

Answer set programming used as computational back-end

Conclusion : −Conditions. with use of negation as failure

Important components:

observed(Event,Instant): an exogenous event at time toccurred(Event,Instant): a legal action at time tholdsat(Fluent,Instant): fluent is true at time tpow(Event),perm(Event),obl(Event,DueEvent,VioEvent):fluents that indicate normsinitiated(Fluent,Instant): fluents to be added to stateterminated(Fluent,Instant): fluents to be deleted from the state

Automatic Conflict Detection

1 Motivation

5 Future Work

Composite Legal Specification

Composite Legal Specification CL with L = {L1, . . . ,Ln}Wrapper for independent legal specification. Individual statetransition.

Composite trace = sequence of exogenous events from all individuallegal specification.

Synchronised Traces: Null events (enull) to fill up the unrecognisedevents in individual traces. DOES NOT change the states.

Conflict traces

Conflicts occur when any two legal specifications disagree on a fluentknown to both of them at the same time instant:

conflict(FX, FY, I) : −holdsat(FX, I),not holdsat(FY, I),

rename(F, FX, X), rename(F, FY, Y),

ifluent(FX), ifluent(FY),

instant(I), inst(X; Y).

Renaming: Contradiction results in no answer set.

Conflict traces

Conflicts occur when any two legal specifications disagree on a fluentknown to both of them at the same time instant:

conflict(FX, FY, I) : −holdsat(FX, I),not holdsat(FY, I),

rename(F, FX, X), rename(F, FY, Y),

ifluent(FX), ifluent(FY),

instant(I), inst(X; Y).

Renaming: Contradiction results in no answer set.

Conflicts Detection

CTR = 〈..., sendOfferLetter , acceptOffer , askStudentship, applyVisa, ...〉University Regulations:

UK Immigration Law:

conflict(perm(workUNI(tingting, 30)), permVI(tingting), 30), 4)conflict(perm(workVI(tingting, 20)), permUNI(tingting), 20), 4)

Conflicts Detection

S0 S1 S2 S3 S4

personUNI(tingting,overseas)perm(sendOfferLetterUNI(tingting))live(university)perm(acceptOfferUNI(tingting))...

perm(sendOfferLetterUNI(tingting))personUNI(tingting,overseas)live(university)perm(askStudentShipUNI(tingting))perm(acceptOfferUNI(tingting))...

personUNI(tingting,overseas)perm(sendOfferLetterUNI(tingting))live(university)obl(workUNI(tingting,30),weekEnd,

withdrawStudentshipUNI)perm(workUNI(tingting,30))...

withdrawStudentshipUNI)

perm(workUNI(tingting,30))

sendOfferLetter(tingting) acceptOffer(tingting) askStudentShip(tingting) enull

UK Immigration Law:

S0 S1 S2 S3 S4

personVI(tingting,overseas)perm(acceptOfferVI(tingting))live(visa)...

live(visa)perm(applyVisaVI(tingting))perm(acceptOfferVI(tingting))personVI(tingting,overseas)obl(applyVisaVI(tingting),arrivalVI(tingting),

illegalImmigrantVI(tingting))...

live(visa)perm(applyVisaVI(tingting))perm(acceptOfferVI(tingting))personVI(tingting,overseas)

perm(workVI(tingting,20))

studentVisaVI(tingting,tier4)...

enull acceptOffer(tingting) enull applyVisa(tingting)

Conflicts Detection

S0 S1 S2 S3 S4

personUNI(tingting,overseas)perm(sendOfferLetterUNI(tingting))live(university)perm(acceptOfferUNI(tingting))...

perm(sendOfferLetterUNI(tingting))personUNI(tingting,overseas)live(university)perm(askStudentShipUNI(tingting))perm(acceptOfferUNI(tingting))...

withdrawStudentshipUNI)perm(workUNI(tingting,30))...

withdrawStudentshipUNI)

perm(workUNI(tingting,30))

sendOfferLetter(tingting) acceptOffer(tingting) askStudentShip(tingting) enull

UK Immigration Law:

S0 S1 S2 S3 S4

personVI(tingting,overseas)perm(acceptOfferVI(tingting))live(visa)...

live(visa)perm(applyVisaVI(tingting))perm(acceptOfferVI(tingting))personVI(tingting,overseas)

perm(workVI(tingting,20))

studentVisaVI(tingting,tier4)...

enull acceptOffer(tingting) enull applyVisa(tingting)

Conflict Resolution via Automatic Revision

1 Motivation

5 Future Work

Conflict Resolution via Theory Revision2

Theory Revision Task is characterized by a tuple 〈P,B,T ,M〉 and T ′,called revised theory, is a solution to the task with cost c(T ,T ′), iff

1 T ′ ⊆ s(M),2 B ∪ T ′ |= P,3 c(T ,T ′) is minimal.

Given a trace CTR which admits a conflict c = conflict(FX ,FY , I )and assume LX � LY :

Inductive Logic Programming produces all possible revisions L′Y :L′Y ∪ (CL \ LY ) ∪ CTR |= ¬c

2Corapi, Domenico, et al. ”Normative design using inductive learning.”Theory and Practice of Logic Programming 11.4-5 (2011): 783-799.

< P, B, T, M >

MC LC L\L Yc

< P, B, T, M >

MC LC L\L Yc

Case Study

Rule 2 : initiated(perm(work(Student, 30)), I) : −occurred(askStudentShip(Student), I),

holdsat(availability, I),

not holdsat(person(Student, overseas), I).

Rule 3 : initiated(obl(work(Student, 30), weekEnd,

withdrawStudentship), I) : −occurred(askStudentShip(Student), I),

Case Study

Rule 2 : initiated(perm(work(Student, 30)), I) : −occurred(askStudentShip(Student), I),

Rule 3 : initiated(obl(work(Student, 30), weekEnd,

withdrawStudentship), I) : −occurred(askStudentShip(Student), I),

Future Work

1 Motivation

5 Future Work

Future Work

Measurement Mechanism of Revision Cost

Ontology Alignment

Interfaces & Tools

Future Work

Thank you for your attention!Any questions?

a model-based approach to the automatic revision of ... · 2 modelling of legal speci cation formal...

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