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17
Universal coalgebra: a theory of systems
, 2000
"... In the semantics of programming, nite data types such as finite lists, have traditionally been modelled by initial algebras. Later final coalgebras were used in order to deal with in finite data types. Coalgebras, which are the dual of algebras, turned out to be suited, moreover, as models for certa ..."
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Cited by 298 (31 self)
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In the semantics of programming, nite data types such as finite lists, have traditionally been modelled by initial algebras. Later final coalgebras were used in order to deal with in finite data types. Coalgebras, which are the dual of algebras, turned out to be suited, moreover, as models for certain types of automata and more generally, for (transition and dynamical) systems. An important property of initial algebras is that they satisfy the familiar principle of induction. Such a principle was missing for coalgebras until the work of Aczel (NonWellFounded sets, CSLI Leethre Notes, Vol. 14, center for the study of Languages and information, Stanford, 1988) on a theory of nonwellfounded sets, in which he introduced a proof principle nowadays called coinduction. It was formulated in terms of bisimulation, a notion originally stemming from the world of concurrent programming languages. Using the notion of coalgebra homomorphism, the definition of bisimulation on coalgebras can be shown to be formally dual to that of congruence on algebras. Thus, the three basic notions of universal algebra: algebra, homomorphism of algebras, and congruence, turn out to correspond to coalgebra, homomorphism of coalgebras, and bisimulation, respectively. In this paper, the latter are taken
On SDSI's Linked Local Name Spaces
 Journal of Computer Security
, 1998
"... Rivest and Lampson have recently introduced SDSI, a Simple Distributed Security Infrastructure. One of the important innovations of SDSI is the use of linked local name spaces. This paper suggests a logical explanation of SDSI's local name spaces, as a complement to the operational explanation given ..."
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Cited by 104 (2 self)
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Rivest and Lampson have recently introduced SDSI, a Simple Distributed Security Infrastructure. One of the important innovations of SDSI is the use of linked local name spaces. This paper suggests a logical explanation of SDSI's local name spaces, as a complement to the operational explanation given in the SDSI definition.
Monodic fragments of firstorder temporal logics: 20002001 A.D.
"... The aim of this paper is to summarize and analyze some results obtained in 20002001 about decidable and undecidable fragments of various firstorder temporal logics, give some applications in the field of knowledge representation and reasoning, and attract the attention of the `temporal community' ..."
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Cited by 48 (8 self)
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The aim of this paper is to summarize and analyze some results obtained in 20002001 about decidable and undecidable fragments of various firstorder temporal logics, give some applications in the field of knowledge representation and reasoning, and attract the attention of the `temporal community' to a number of interesting open problems.
A Calculus of Transition Systems (towards Universal Coalgebra)
 In Alban Ponse, Maarten de Rijke, and Yde Venema, editors, Modal Logic and Process Algebra, CSLI Lecture Notes No
, 1995
"... By representing transition systems as coalgebras, the three main ingredients of their theory: coalgebra, homomorphism, and bisimulation, can be seen to be in a precise correspondence to the basic notions of universal algebra: \Sigmaalgebra, homomorphism, and substitutive relation (or congruence). ..."
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Cited by 25 (1 self)
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By representing transition systems as coalgebras, the three main ingredients of their theory: coalgebra, homomorphism, and bisimulation, can be seen to be in a precise correspondence to the basic notions of universal algebra: \Sigmaalgebra, homomorphism, and substitutive relation (or congruence). In this paper, some standard results from universal algebra (such as the three isomorphism theorems and facts on the lattices of subalgebras and congruences) are reformulated (using the afore mentioned correspondence) and proved for transition systems. AMS Subject Classification (1991): 68Q10, 68Q55 CR Subject Classification (1991): D.3.1, F.1.2, F.3.2 Keywords & Phrases: Transition system, bisimulation, universal coalgebra, universal algebra, congruence, homomorphism. Note: This paper will appear in `Modal Logic and Process Algebra', edited by Ponse, De Rijke and Venema [PRV95]. 2 Table of Contents 1 Introduction : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : ...
A Logic for Acting, Sensing and Planning
 In Proc. of the 14th International Joint Conference on Artificial Intelligence
, 1995
"... This paper is a first attempt towards a theory for reactive planning systems, i.e. systems able to plan and control execution of plans in a partially known and unpredictable environment. We start from an experimental real world application developed at IRST, discuss some of the fundamental requireme ..."
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Cited by 14 (3 self)
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This paper is a first attempt towards a theory for reactive planning systems, i.e. systems able to plan and control execution of plans in a partially known and unpredictable environment. We start from an experimental real world application developed at IRST, discuss some of the fundamental requirements and propose a formal theory based on these requirements. The theory takes into account the following facts: (1) actions may fail, since they correspond to complex programs controlling sensors and actuators which have to work in an unpredictable environment; (2) actions need to acquire information from the real world by activating sensors and actuators; (3) actions need to generate and execute plans of actions, since the planner needs to activate different special purpose planners and to execute the resulting plans.
Evolution of Collective Commitment during Teamwork
, 2003
"... In this paper we aim to describe dynamic aspects of social and collective attitudes in teams of agents involved in Cooperative Problem Solving (CPS). Particular attention is given to the strongest motivational attitude, collective commitment, and its evolution during team action. First, building ..."
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Cited by 13 (3 self)
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In this paper we aim to describe dynamic aspects of social and collective attitudes in teams of agents involved in Cooperative Problem Solving (CPS). Particular attention is given to the strongest motivational attitude, collective commitment, and its evolution during team action. First, building on our previous work, a logical framework is sketched in which a number of relevant social and collective attitudes is formalized, leading to the planbased definition of collective commitments.
Intensional HTML 2: A Practical Approach
, 1998
"... Intensional HTML addresses the problem of providing a multiversioned Web site, without the penalties usually associated with largescale copying and modification of pages (the usual approach). IHTML uses two key ideas. First, the server uses a bestfit algorithm to find the appropriate file when so ..."
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Cited by 7 (0 self)
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Intensional HTML addresses the problem of providing a multiversioned Web site, without the penalties usually associated with largescale copying and modification of pages (the usual approach). IHTML uses two key ideas. First, the server uses a bestfit algorithm to find the appropriate file when some version of a page is requested. If the exact version requested is not present, the closest match is used. Second, anchors are interpreted as being generic (or intensional, as we will say): an anchor does not link to a particular page, but to a family of versions of a page.
Knowledge on Treelike Spaces
 Studia Logica
, 1997
"... This paper presents a bimodal logic for reasoning about knowledge during knowledge acquisition. One of the modalities represents (effort during) nondeterministic time and the other represents knowledge. The semantics of this logic are treelike spaces which are a generalization of semantics used fo ..."
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Cited by 4 (0 self)
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This paper presents a bimodal logic for reasoning about knowledge during knowledge acquisition. One of the modalities represents (effort during) nondeterministic time and the other represents knowledge. The semantics of this logic are treelike spaces which are a generalization of semantics used for modeling branching time and historical necessity. A finite system of axiom schemes is shown to be canonically complete for the formentioned spaces. A characterization of the satisfaction relation implies the small model property and decidability for this system. 1