This page summarises the known typos/bugs, ommissions, and clarifications for RaRA. If you come across any more, please let me know.

Second Printing

I managed to correct some typos for the second printing of the book (March 2002): here are the corrected pages for this printing.

Typos/Bugs

• Chapter 4, pages 76 and 79: I defined the semantics of predicates via the function Phi with respect to time points. They should have been defined with respect to situations, i.e., the function Phi on p76 should be a function Phi : Pred x W x T ->..., instead of Phi : Pred x T -> ... and the semantic rule for predicates on page 79 should be ``is a member of Phi(P,w,t)'', not ``is a member of Phi(P,t)''. (Corrected in 2nd printing.)

• Chapter 4, page 79: in the seventh semantic rule, ``Goal'' should be ``Des''. This is a hangover from a previous version of LaTeX macros; as far as I am aware, this is the only place in the book that I used ``Goal'' instead of ``Des'', but any other occurrences of ``Goal'' should also be read as ``Des''. (Corrected in 2nd printing.)

• Chapter 4, page 85: there are two typos in the proof of Theorem 4.3(3): line 5 from the bottom should read ``(M,V,w'',t) |= phi'', not ``(M,V,w'',t) |= (Bel i phi)'' and similarly line 8 from the bottom. Thanks to Joxe Gaintzarain Ibarmia for pointing this out.

• Chapter 4, page 88: in Theorem 4.8(1), there should be an ``E'' (existential path quantifier) before (Happens a')? on the right hand side of the implication. (Because ``Happens'' is a path formula.) Thanks to Joxe Gaintzarain Ibarmia for pointing this out. (Corrected in 2nd printing.)

• Chapter 5, page 93: I ommitted a (very) important part of the definition of subworlds. For w to be a subworld of w', then w must contain fewer paths than w', but otherwise, the two worlds are identical --- they agree on the interpretation of predicates, constants, and BDI modalities. (Corrected in 2nd printing.)

• Chapter 5, page 108. Last paragraph. It should be "the first of these properties, (5.37)'' instead of ``the first of these properties (5.25)'' Thanks to Joxe Gaintzarain Ibarmia for pointing this out.

• Chapter 5, page 109: the text would read better if the 1st sentence following formula (5.39) was deleted. Also, it should be ``sub'' rather than ``sup'' in every row of Table 5.6. Thanks to Gordon Beavers, Henry Hexmoor, and Joxe Gaintzarain Ibarmia for pointing this out. (Corrected in 2nd printing.)

• Chapter 5, page 110: Table 5.7. BDI-R2: it should be ``Bel => Des => Int'' instead of ``Int => Des => Bel''. Thanks to Joxe Gaintzarain Ibarmia for pointing this out. (Corrected in 2nd printing.)

• Chapter 6, page 116. In the definition of reachability, the 1st world in the sequence of worlds should be w_0, not w_1. In the last paragraph, third line, the proof should read ``w' in B^w_t'' instead of ``w' in B^w'_t''. Thanks to Joxe Gaintzarain Ibarmia for pointing this out.

• Chapter 7, page 137: In the third paragraph, the sentence starting ``The answer I adopt here...'' is misleading. It would be better to have written ``The answer I adopt here is that the best you can do is to convince me that you intend that I believe this state of affairs.''

• Chapter 8, page 151: In the sixth line of the proof of Theorem 8.2, the the ``exists alpha'' should be deleted from the formula at the start of the line.

• Chapter 8, page 157: In the definition of FormTeam, an agent doesn't need to inform the team that they can jointly achieve the goal (they will already be aware of this). It suffices to define FormTeam as {RequestTh i g alpha phi}, but a better definition is (Bel i (JCan g phi))?; {RequestTh i g alpha phi}. (the agent requests the grouo while believing that they can do it).

• Chapter 8, page 159: In the definition of J-Attempt, fourth line, it should read (Achvs alpha psi), not (Achvs alpha;psi?). (Corrected in 2nd printing.)

Omissions

• Chapter 2: I omitted to mention the work of John Pollock, on architectures for rational agents. Pollock's OSCAR architecture was developed with some similar concerns in mind to the BDI model. I should have cited John's book Cognitive Carpentry (MIT Press, 1995).

• Chapter 8: I omitted to mention the work of Milind Tambe and colleagues on the STEAM framework for cooperative problem solving, which makes use of a joint-intention model for cooperative problem solving. I should have cited M. Tambe, 1997, ``Towards Flexible Teamwork'', In Journal of Artificial Intelligence Research, Volume 7, Pages 83-124.

Clarifications

• Chapter 2, page 41: the graph doesn't quite show that what happens when dynamism tends to a maximum. Thanks to Gordon Beavers and Henry Hexmoor for raising this issue.

• Chapter 4: Time points. Finally, a note on terminology. The term ``state formula'' is as used in the (extensive) literature on branching temporal logic. Since this literature is very well established, I chose to leave it unchanged in the book, although I don't use states as such. The terms ``situation'' and ``time point'' are from the BDI literature (Rao and Georgeff), and for similar reasons I chose not to change them in the book. As ever, terminology is not ideal. Time points are emphatically not intended to correspond to ``times of the day''. In fact, there are comparatively few temporal logics that I am aware of which attempt to do this. In fact, time points are somewhat more like states. Thanks to Gordon Beavers and Henry Hexmoor for raising this issue.