Artificial Intelligence and Law

, Volume 16, Issue 1, pp 25–52 | Cite as

A computational framework for institutional agency

  • Guido Governatori
  • Antonino Rotolo


This paper provides a computational framework, based on defeasible logic, to capture some aspects of institutional agency. Our background is Kanger-Lindahl-Pörn account of organised interaction, which describes this interaction within a multi-modal logical setting. This work focuses in particular on the notions of counts-as link and on those of attempt and of personal and direct action to realise states of affairs. We show how standard defeasible logic (DL) can be extended to represent these concepts: the resulting system preserves some basic properties commonly attributed to them. In addition, the framework enjoys nice computational properties, as it turns out that the extension of any theory can be computed in time linear to the size of the theory itself.


Institutional agency Agent societies Counts-as Defeasible logic 


  1. Antoniou G, Billington D, Governatori G, Maher MJ (2000a) A flexible framework for defeasible logics. In: Proc AAAI 2000. AAAI Press, pp 401–405Google Scholar
  2. Antoniou G, Billington D, Governatori G, Maher MJ (2001) Representation results for defeasible logic. ACM Transact Comput Logic 2(2):255–287CrossRefMathSciNetzbMATHGoogle Scholar
  3. Antoniou G, Billington D, Governatori G, Maher MJ, Rock A (2000b) A family of defeasible reasoning logics and its implementation. In: Proc ECAI 2000. IOS Press, pp 459–463Google Scholar
  4. Artosi A, Governatori G, Rotolo A (2002) Labelled tableaux for non-monotonic reasoning: cumulative consequence relations. J Logic Comput 12(6):1027–1060zbMATHCrossRefMathSciNetGoogle Scholar
  5. Billington D (1993) Defeasible logic is stable. J Logic Comput 3:370–400CrossRefMathSciNetGoogle Scholar
  6. Boella G, van der Torre L (2004) Regulative and constitutive norms in normative multiagent systems. In: Proc KR 2004. Morgan Kaufmann, pp 255–266Google Scholar
  7. Broersen J (2004) Action negation and alternative reductions for dynamic deontic logics. J Appl Logic 2(1):153–168zbMATHCrossRefMathSciNetGoogle Scholar
  8. Castelfranchi C, Falcone R (1998) Towards a theory of delegation for agent-based systems. Robot Auton Agents 24:141–157CrossRefGoogle Scholar
  9. Chellas B (1980) Modal logic. An introduction. Cambridge University PressGoogle Scholar
  10. Conte R, Dellarocas C (2001) Social order in multiagent systems. KluwerGoogle Scholar
  11. Demolombe R, Herzig A (2004) Obligation change in dependence logic and situation calculus. In: Lomuscio A, Nute D (eds) Proc Deon 2004, LNAI 3065. Springer, pp 57–73Google Scholar
  12. Elgesem D (1997) The modal logic of agency. Nordic J Philos Logic 2:1–48zbMATHMathSciNetGoogle Scholar
  13. Farrell AD, Sergot M, Sallé M, Bartolini C (2005) Using the event calculus for tracking the normative state of contracts. Int J Cooper Inform Syst 4(2–3):99–129CrossRefGoogle Scholar
  14. Gelati J, Governatori G, Rotolo A, Sartor G (2004) Normative autonomy and normative co-ordination: declarative power, representation, and mandate. Artif Intell Law 12(1–2):53–81CrossRefGoogle Scholar
  15. Goldman A (1970) A theory of human action. Prentice Hall, PrincetonGoogle Scholar
  16. Governatori G, Pham DH (2005) A semantic web based architecture for e-contracts in defeasible logic. In: Proc RuleML 2005, LNCS 3791. Springer, pp 145–159Google Scholar
  17. Governatori G, Rotolo A (2005) On the axiomatization of Elgesem’s logic of agency and ability. J Philos Logic 34(4):403–431zbMATHCrossRefMathSciNetGoogle Scholar
  18. Governatori G, Rotolo A, Sartor G (2006) Temporalised normative positions in defeasible logic. In: Proc ICAIL’05. ACM, pp 25–43Google Scholar
  19. Governatori G, Rotolo A, Padmanabhan V (2006) The cost of social agents. In: Proc AAMAS’06. ACM, pp 513–520Google Scholar
  20. Grossi D, Meyer J-J, Dignum F (2005) Modal logic investigations in the semantics of counts-as. In: Proc ICAIL’05. ACM, pp 1–9Google Scholar
  21. Grossi D, Meyer J-J, Dignum F (2006) Counts-as: Classification or constitution? An answer using modal logic. In: Proc Deon’06, LNCS 4048. Springer, pp 115–130Google Scholar
  22. Halpern JY, Moses YO (1990) A guide to completeness and complexity for modal logics of knowledge and belief. Artif Intell 54:319–379CrossRefMathSciNetGoogle Scholar
  23. Horty JF (2001) Agency and deontic logic. Oxford University Press, OxfordzbMATHGoogle Scholar
  24. Jones A, Parent X, Stolpe A (2003) Private communicationGoogle Scholar
  25. Jones A, Sergot M (1996) A formal characterisation of institutionalised power. J IGPL 3:427–443CrossRefMathSciNetGoogle Scholar
  26. Jones AJ (forthcoming) A logical framework. In: Pitt J (ed) Open agent societies: normative specifications in multi-agent systems. WileyGoogle Scholar
  27. Kanger S (1972) Law and logic. Theoria 38:105–32zbMATHMathSciNetCrossRefGoogle Scholar
  28. Lindahl L (1977) Position of change: a study in law and logic. ReidelGoogle Scholar
  29. Maher MJ (2001) Propositional defeasible logic has linear complexity. Theory Practice Logic Program 1(6):691–711zbMATHMathSciNetGoogle Scholar
  30. Makinson D (1986) On the formal representation of rights relations. J Philos Logic 15:403–425CrossRefMathSciNetzbMATHGoogle Scholar
  31. Norman T, Reed C (2001) Delegation and responsibility. In: Castelfranchi C, Lesperance Y (eds) Proc Intelligent Agents VII, LNAI 1986. Springer, pp 136–149Google Scholar
  32. Nute D (1994) Defeasible logic. In: Handbook of logic in artificial intelligence and logic programming, vol 3. Oxford University Press, pp 353–395Google Scholar
  33. Pitt J (ed) (forthcoming) Open agent societies: normative specifications in multi-agent systems. WileyGoogle Scholar
  34. Prakken H (1997) Logical tools for modelling legal argument. KluwerGoogle Scholar
  35. Pörn I (1977) Action theory and social science: some formal models. ReidelGoogle Scholar
  36. Royakkers L (2000) Combining deontic and action logics for collective agency. In: Legal knowledge and information systems (Jurix). IOS Press, pp 135–146Google Scholar
  37. Santos F, Carmo J (1996) Indirect action. Influence and responsibility. In: Brown M, Carmo J (eds) Deontic logic, agency and normative systems. Springer, pp 194–215Google Scholar
  38. Santos F, Jones A, Carmo J (1997) Action concepts for describing organised interaction. In: Proc 13th HICSS. IEEE Computer Society Press, pp 373–382Google Scholar
  39. Searle J (1995) The construction of social reality. Penguin PressGoogle Scholar
  40. Segerberg K (1992) Getting started: beginnings in the logic of action. Studia Logica 51:347–358CrossRefMathSciNetzbMATHGoogle Scholar
  41. Sergot M (forthcoming) The Language (C/C +)++. In: Pitt J (ed), Open agent societies: normative specifications in multi-agent systems. WileyGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2007

Authors and Affiliations

  1. 1.School of Information Technology and Electrical EngineeringThe University of QueenslandBrisbaneAustralia
  2. 2.CIRSFID, Law FacultyUniversity of BolognaBolognaItaly

Personalised recommendations