NB. On Wednesday
November 27th, 2013 and Monday December 9th, 2013 there will be no lectures
This course is about the theory
and realisation of so-called intelligent agents, pieces
of software that display some degree of autonomy, realised
by incorporating `high-level cognitive / mental attitudes' into both
modelling and implementation of this kind of software. As such,
the subject of intelligent agents is at the cross-roads of the fields
of artificial intelligence and mainstream computer science, in particular
software engineering. These mental attitudes comprise 'informational'
and 'motivational' ones and are often of the so-called BDI kind, dealing
with 'beliefs', 'desires' and 'intentions' of agents. The agent
concept calls for an integration of several topics in artificial
intelligence, such as knowledge representation and reasoning (in
particular reasoning about action and change) and planning.
Agent technology, as the field
is generally called, has a great potential of applications,
ranging from intelligent personal assistants to e-commerce
and robotics (where in the latter case often the term 'cognitive
robotics' is used).
In the course we will devote
much time to the philosophical and theoretical (mostly
logical) foundations of the area of intelligent agents, and
then go on with describing ways of realising them by special
architectures and so-called agent-oriented programming languages
in which one can program the 'mental states' of agents.
This course presents the introductory theory for the agent-directed
courses in the Master programme and gives a background for courses
such as MAS and MAP.
Docent / Lecturer
Downloadable at the moment:
(John-Jules Meyer, Agent Technology, in: Encyclopedia of Computer Science
and Engineering, Vol. 1 (B.W. Wah, ed.), Wiley, Hoboken, NJ, 2009, pp.42-49.
Modal Logics for Intelligent Agents
BDI Logics (Meyer, Broersen & Herzig)
Intelligent Agents by Michael Wooldridge
Levesque, H.; Pirri, F.; and Reiter, R. 1998.
Foundations for the Situation Calculus
no direct material for exam)
paper in JAAMAS
(material upto and including
Cohen & Levesque
(P.R. Cohen & H.J. Levesque,
Intention Is Choice with Commitment, Artificial
Intelligence 42, 1990, pp. 213-261.)
(A.S. Rao & M.P. Georgeff, Modeling
Rational Agents within a BDI-Architecture, in Proc.
KR'91, Morgan Kaufmann, 1991, pp. 473-484.)
(W. van der Hoek, B. van Linder & J.-J. Ch. Meyer, An Integrated
Modal Approach to Rational Agents, Report UU-CS-1997-06, UU, 1997; also
in: M. Wooldridge & A. Rao (eds.), Foundations of Rational Agents, Applied
Logic Series 14, Kluwer, Dordrecht, 1998, pp. 133-168) and
(J.-J.Ch. Meyer, W. van der Hoek & B. van Linder, A Logical Approach
to the Dynamics of Commitments, CKI Preprint Series No 14, 1999, also in:
AI Journal 113, 1999, pp. 1-40) are the basic papers on KARO
(Y. Shoham, Agent-Oriented Programming, Artificial Intelligence 60 (1),
1993, pp. 51-92) (only background, no direct material for exam).
Slides are downloadable.
However, some caution is in order: due to fonts used on my machine
printing errors may occur (e.g. deleted or wrong symbols). Unfortunately
this is unavoidable. So, always check your prints.
Modal logic II
Errata:: p 251, Thm 7.2, 3rd
line: "INTEND2" -> "INTEND1"; pagina 236, prop 4.2, first part of first
clause "p \/ q". should read "p /\ q".
(Slides on informational attitudes are not
(STRIPS IS NOT EXAMINATION MATERIAL)
(Examination material: upto and including slide 23!!!)
Erratum: p 14, def 9: in conclusion of transition
rule: "\pi" should read "\pi \eta"
example AGENT0 program
example 3APL program
Regularly homework will be given
to enable you to practise with the material and prepare
yourself for the examination. This home work will be discussed
(partially) during the werkcolleges. It does not give you direct
credits for the examination. It is only for necessary practice.
1. Think about the realisability
of Asimov's laws of robotics. How difficult are they?
What kind of AI techniques are necessary to be able to implement
2.(a) Show the validity of the basic
property on slide 67, i.e. show that it holds in any world in any
(b) Prove the correspondences of slide 70 in the
following sense: show that Kripke models that satisfy the respective
conditions on the accessibility relation R make the corresponding
modal formula true in any world.
3. Prove Prop 3.15, 3.16, 3.21, 3.22,
3.23, 3.26, 3.28 of Cohen & Levesque formally, using the
definiition of the semantics.
4. Prove Prop. 3.8, 3.9, 3.11, 3.13,
4.5 (as precisely as possible). Challenge: does Theorem
7.2 hold for any actions a and e?
5. Prove Prop. 3.8 and 3.9 of Cohen &
Levesque again, but now in the framework of (P)LTL (this
is much simpler!).
6. Check whether the following formulas
are valid in CTL*:
(a) A psi -> E psi (b) E box psi ->
A diam psi (c) A diam psi -> E box psi
7. Construct BDI-models Rao & Georgeff-style
for the following formulas:
(a) GOAL(optional \Box
(b) optional \Diamond
inevitable \Box GOAL p
(c) inevitable \Box optional
\Diamond GOAL p & ¬(optional \Diamond inevitable
\Box GOAL p)
8. (a) Prove the validity
of GOAL(alpha) -> BEL(alpha) for alpha = optional(psi)
under the B-G condition (see slides).
(b) Prove Theorems 1 and
2 in the article of Rao & Georgeff.
9. Show that in dynamic logic
(and so also in KARO) the following holds:
(a) |= [alpha1 ; alpha2]
phi <-> [alpha1]([alpha2] phi )
(b) for deterministic
alpha: |= <alpha>(phi & psi) <->
( <alpha>phi & <alpha>psi). Also show that this
does not hold for general alpha (that may thus be non-deterministic)!
10. Regarding KARO logic:
(a) Show |= A(alpha1 ; alpha2) <-> A(alpha1)
& [alpha1] A(alpha2) under the condition for function C on
(b) Show for deterministic, non-failing
actions alpha1 and alpha2 the validity of:
Can( alpha1 ; alpha2 , phi )
<-> Can ( alpha1 , PracPoss ( alpha2 , phi ))
(Hint: first show that now it holds also that:
A( alpha1; alpha2 ) <-> (A alpha1 & <alpha1>
(c) Show: |= phi -> psi does NOT imply |=
Goal(phi) -> Goal(psi)
(d) Prove the first 3
validities on slide 166 (using the semantics on slide 165).
(e) Compare the logics of Cohen & Levesque,
Rao & Georgeff and KARO. What are similarities and differences?
11. Exercises situation
calculus and STRIPS planning
(downloadable Word document)
12. (a) Prove the Theorem on slide 18 of Thielscher.
(b) Exercise about regression
in situation calculus
(downloadable Word document)
13. (a) Compare deliberative and reactive agent
architectures: what situations call for which architecture?
(b) Discuss the problems occurring when realising
a layered hybrid agent architecture, and how to solve these.
(c) Discuss (dis)advantages of horizontally
versus vertically layered hybrid agent architectures.
14. Consider the following exercise:
(downloadable Word document)
Sample elaborations of homework
Here you can find a couple of elaborated exercises to show how
this should be done 3.8
There will be a written examination
which is ' limited
open book' , i.e.
only clean (non-annotated) versions of the study
material (slides, copies of articles) may be used.
HOWEVER THE ELABORATION OF THE HOMEWORK EXERCISES AS PROVIDED
AT THE INSTRUCTION HOURS IS NOT ALLOWED!!! A sample exam can
be found here
For persons who (think they) do
not have sufficient background in (modal) logic (as e.g.
been treated in courses like Logic for AI), I recommend to
study the first two chapters of the book Meyer & van der
Hoek, Epistemic Logic for AI and Computer Science . (This
also contains exercises with answers.) By now there is a paperback
version of this book, but it should also be available in the library.
File last modified at
NOVEMBER 24, 2013