It is most easily available by anonymous ftp from crl.nmsu.edu in the directory pub/non-lexical/ViewFinder The files in that directory are: ViewFinder-A4.tar.Z = A4 postscript version of my dissertation ViewFinder-A5.tar.Z = A5 version of same ViewFinder-US.tar.Z = US letter version ViewGen.tar.Z = the ViewGen system patch1 = patch for ViewGen patch1.readme = explanation of how to apply the patch vf-hetis.tar.Z = Multiple Defeasible Inheritance Reasoner as described in various papers, as well as in the thesis. Brief description of ViewGen follows: ViewGen: ViewGen.tar.Z available by anonymous ftp from -- ViewGen (a viewpoint generator) is a prolog program that implements a "Belief Ascription Algorithm" as described in Ballim & Wilks (see the bibliography section on User Modelling). This can be seen as a form of agent modelling tool, which allows for the generation of arbitrarily deep nested belief spaces based on the system's own beliefs, and on beliefs that are typically held by groups of agents. The theory of belief ascription upon which it is based is described in detail in "Artificial Believers" by Ballim & Wilks (Lawrence Erlbaum Associates), and a general framework for attributing and maintaining nested propositional attitudes is described in Afzal Ballim's dissertation which is archived with the Viewgen program (in the files ViewFinder-{A4/A5/US}.tar.Z, the variable part indicating the format of the PostScript file). Brief description of my dissertation follows: ViewFinder: A Framework for Representing, Ascribing and Maintaining Nested beliefs of Interacting Agents Afzal Ballim Dept. of Computer Science, University of Geneva, Switzerland Interacting with agents in an intelligent manner means that the computer program is able to adapt itself to the specific requirements of agents. The dissertation is concerned with an important feature necessary for this ability to adapt: the use of models of the beliefs and knowledge of the interacting agents. The objective of this dissertation is to detail a theory of belief, by which is meant a theory of how the contents of nested belief models are formed. The work is motivated by (i) the aspects of representation, formation, and revision of nested belief models that have been neglected, and (ii) the lack of a unifying framework for all of these features of nested beliefs. In much research involving models of the beliefs of agents, the models used are pre-given. While this is sufficient in highly constrained domains it is inappropriate in general. In more complex domains it is necessary to dynamically generate these models. This dissertation is directly concerned with the problems of dynamically creating such nested models of the beliefs of agents. The major contributions of this work are: 1) Investigation of the problems of using stereotypes for generating nested belief models. 2) Detailed work on using belief perturbation as an ascription method. 3) Development of parameterized ``belief ascription operators'' to characterize the ascription process. 4) Elaborated proposal for an approach to belief ascription that captures the best of perturbation and stereotype approaches, but is more general. 5) Comparison of belief ascription with belief interpretation. 6) Consideration of belief revision in a system that maintains nested beliefs. 7) Formulation of a generalized framework for dealing with nested propositional attitudes, based on the notion of ``environments.'' 8) Reformulation of ascription operators as environment projection operators. 9) Demonstration of how environment projection can can be seen as a fundamental operator underlying many important processes in AI, including belief ascription, inheritance reasoning, truth maintenance, belief revision, merging of intensional descriptions, and metaphor generation. An environment framework may thus serve as a basis for investigation, development, and implementation of all of these processes.