TEAM LinG Lecture Notes in Computer Science 3170 Commenced Publication in 1973 Founding and Former Series Editors: Gerhard Goos, Juris Hartmanis, and Jan van Leeuwen Editorial Board David Hutchison Lancaster University, UK Takeo Kanade Carnegie Mellon University, Pittsburgh, PA, USA Josef Kittler University of Surrey, Guildford, UK Jon M Kleinberg Cornell University, Ithaca, NY, USA Friedemann Mattern ETH Zurich, Switzerland John C Mitchell Stanford University, CA, USA Moni Naor Weizmann Institute of Science, Rehovot, Israel Oscar Nierstrasz University of Bern, Switzerland C Pandu Rangan Indian Institute of Technology, Madras, India Bernhard Steffen University of Dortmund, Germany Madhu Sudan Massachusetts Institute of Technology, MA, USA Demetri Terzopoulos New York University, NY, USA Doug Tygar University of California, Berkeley, CA, USA Moshe Y Vardi Rice University, Houston, TX, USA Gerhard Weikum Max-Planck Institute of Computer Science, Saarbruecken, Germany TEAM LinG This page intentionally left blank TEAM LinG Philippa Gardner Nobuko Yoshida (Eds.) CONCUR 2004 – Concurrency Theory 15th International Conference London, UK, August 31 – September 3, 2004 Proceedings Springer TEAM LinG eBook ISBN: Print ISBN: 3-540-28644-6 3-540-22940-X ©2005 Springer Science + Business Media, Inc Print ©2004 Springer-Verlag Berlin Heidelberg All rights reserved No part of this eBook may be reproduced or transmitted in any form or by any means, electronic, mechanical, recording, or otherwise, without written consent from the Publisher Created in the United States of America Visit Springer's eBookstore at: and the Springer Global Website Online at: http://ebooks.springerlink.com http://www.springeronline.com TEAM LinG Preface This volume contains the proceedings of the 15th International Conference on Concurrency Theory (CONCUR 2004) held in the Royal Society, London, UK, from the 31st August to the 3rd September, 2004 The purpose of the CONCUR conferences is to bring together researchers, developers and students in order to advance the theory of concurrency and promote its applications Interest in this topic is continually growing, as a consequence of the importance and ubiquity of concurrent systems and their applications, and of the scientific relevance of their foundations The scope covers all areas of semantics, logics, and verification techniques for concurrent systems Topics include concurrency-related aspects of: models of computation, semantic domains, process algebras, Petri nets, event structures, real-time systems, hybrid systems, decidability, model-checking, verification techniques, refinement techniques, term and graph rewriting, distributed programming, logic constraint programming, object-oriented programming, typing systems and algorithms, case studies, tools and environments for programming and verification This volume starts with four invited papers from Sriram Rajamani, Steve Brookes, Bengt Jonsson and Peter O’Hearn The remaining 29 papers were selected by the program committee from 134 submissions, a record number of submissions to CONCUR The standard was extremely high and the selection difficult Each submission received at least three reports, reviewed by the program committee members or their subreferees Once the initial reviews were available, we had 16 days for paper selection and conflict resolution We would like to thank all members of the CONCUR 2004 Program Committee for their excellent work throughout the intensive selection process, together with many subreferees who assisted us in the evaluation of the submitted papers The conference includes talks by several invited speakers: invited seminars by David Harel (Weizmann Institute) and Sriram Rajamani (Microsoft Research, Redmond), and invited tutorials by Steve Brooks (Carnegie-Mellon) and Peter O’Hearn (Queen Mary, University of London), and by Bengt Jonsson (Uppsala) The conference has 11 satellite events: Workshop on Structural Operational Semantics (SOS 2004), organised by Luca Aceto 11th International Workshop on Expressiveness in Concurrency (EXPRESS 2004), organised by Flavio Corradini II Workshop on Object-Oriented Developments (WOOD 2004), organised by Viviana Bono 3rd International Workshop on Foundations of Coordination Languages and Software Architectures (FOCLASA 2004), organised by Jean-Marie Jacquet 2nd International Workshop on Security Issues in Coordination Models, Languages and Systems (SECCO 2004), organised by Gianluigi Zavattaro TEAM LinG VI Preface Workshop on Concurrent Models in Molecular Biology (BIOCONCUR 2004), organised by Anna Ingolfsdottir Global Ubiquitous Computing (FGUC 2004), organised by Julian Rathke 3rd International Workshop on Parallel and Distributed Methods in Verification (PDMC 2004), organised by Martin Leucker 4th International Workshop on Automated Verification of Critical Systems (AVoCS 2004), organised by Michael Huth 1st International Workshop on Practical Applications of Stochastic Modelling (PASM 2004), organised by Jeremy Bradley 6th International Workshop on Verification of Infinite-State Systems (INFINITY 2004), organised by Julian Bradfield We would like to thank the conference organisation chair Iain Phillips, the local organisers Alex Ahern and Sergio Maffeis, the workshop organisation chairs Julian Rathke and Vladimiro Sassone, and the workshop organisers Finally we thank the invited speakers, invited tutorial speakers and the authors of submitted papers for participating in what promises to be a very interesting conference We gratefully acknowledge support from the Department of Computing, Imperial College London, the Engineering and Physical Sciences Research Council (EPSRC), Microsoft Research in Cambridge, and the Royal Society June 2004 Philippa Gardner and Nobuko Yoshida TEAM LinG Organisation CONCUR Steering Committee Roberto Amadio (Université de Provence, Marseille, France) Jos Baeten (Technische Universiteit Eindhoven, Netherlands) Eike Best (Carl von Ossietzky Universität Oldenburg, Germany) Kim G Larsen (Aalborg University, Denmark) Ugo Montanari (Università di Pisa, Italy) Scott Smolka (State University of New York at Stony Brook, USA) Pierre Wolper (Université de Liège, Belgium) Program Committee Luca Aceto (Aalborg University, Denmark) Luca de Alfaro (University of California, Santa Cruz, USA) Bruno Blanchet (Saarbrücken, Germany/École Normale Supérieure, France) Steve Brookes (Carnegie Mellon University, USA) Philippa Gardner (Imperial College London, UK, Co-chair) Paul Gastin (Université Paris 7, France) (Technical University of Ostrava, Czech Republic) Joost-Pieter Katoen (University of Twente, Netherlands) Dietrich Kuske (Technische Universität Dresden, Germany) Cosimo Laneve (Università di Bologna, Italy) Michael Mendler (Otto-Friedrich-Universität Bamberg, Germany) Ugo Montanari (Università di Pisa, Italy) Catuscia Palamidessi (INRIA Futurs Saclay and LIX, France) Vladimiro Sassone (University of Sussex, UK) PS Thiagarajan (National University of Singapore, Singapore) Antti Valmari (Tampere University of Technology, Finland) Wang Yi (Uppsala Universitet, Sweden) Nobuko Yoshida (Imperial College London, UK, Co-chair) Referees Parosh Abdulla Joaquin Aguado Rajeev Alur Roberto Amadio Christopher Anderson Suzana Andova Christel Baier Michael Baldamus Paolo Baldan Howard Barringer Gerd Behrmann Nick Benton Béatrice Bérard Martin Berger Marco Bernardo TEAM LinG VIII Organisation Bernard Berthomieu Bernard Boigelot Roland Bol Frank de Boer Michele Boreale Ahmed Bouajjani Patricia Bouyer Julian Bradfield Ed Brinksma Roberto Bruni Glenn Bruns Nadia Busi Cristiano Calcagno Luca Cardelli Josep Carmona Samuele Carpineti Iliano Cervesato Tom Chothia Giovanni Conforti Andrea Corradini Véronique Cortier Dennis Dams Philippe Darondeau Alexandre David Jennifer Davoren Conrado Daws Giorgio Delzanno Stephane Demri Henning Dierks Alessandra Di Pierro Dino Distefano Marco Faella Lisbeth Fajstrup Alessandro Fantechi Jérôme Feret Gianluigi Ferrari Elena Fersman Emmanuel Fleury Riccardo Focardi Marcelo Fiore Wan Fokkink Cédric Fournet Laurent Fribourg Murdoch Gabbay Maurizio Gabbrielli Fabio Gadducci Simon Gay Jaco Geldenhuys Neil Ghani Giorgio Ghelli Paola Giannini Gregor Goessler Goerges Gonthier Daniele Gorla Olga Greinchtein Dilian Gurov Elsa Gunter Peter Habermehl John Hakansson Henri Hansen Jens Hansen Zdenek Hanzalek Thomas Hildebrandt Daniel Hirschkoff Kohei Honda Michael Huth Hans Hüttel Radha Jagadeesan Somesh Jha Ranjit Jhala Bengt Jonsson Gabriel Juhas Marcin Jurdzinski Antero Kangas Antti Kervinen Mike Kishinevsky Bartek Klin Barbara König Juha Kortelainen Martin Kot Stephan Kreutzer Lars Kristensen Kare Kristoffersen Narayan Kumar Orna Kupferman Marta Kwiatkowska Jim Laird Ivan Lanese Martin Lange Rom Langerak Franỗois Laroussinie Kim Larsen Paola Lecca Fabrice Le Fessant James Leifer Francesca Levi Kamal Lodaya Markus Lohrey Robert Lorenz Gerald Luettgen Markus Lumpe Damiano Macedonio Angelika Mader Sergio Maffeis A Maggiolo-Schettini Pritha Mahata Jean Mairesse Rupak Majumdar Andreas Maletti Fabio Martinelli Narciso Marti-Oliet Angelika Mader Richard Mayr Hernan Melgratti Oskar Mencer Massimo Merro Marino Miculan Dale Miller Robin Milner Sebastian Moedersheim Faron Moller Angelo Montanari Rémi Morin Larry Moss Madhavan Mukund Andrzej Murawski Anca Muscholl Uwe Nestmann Peter Niebert Mogens Nielsen Barry Norton Robert Palmer Jun Pang Matthew Parkinson Justin Pearson TEAM LinG Organisation Christian Pech Paul Pettersson Iain Phillips Michele Pinna Marco Pistore Lucia Pomello Franck Pommereau Franỗois Pottier John Power Rosario Pugliese Antti Puhakka Alexander Rabinovich R Ramanujam Julian Rathke Martin Raussen Wolfgang Reisig Michel Reniers Arend Rensink James Riely Grigore Rosu Olivier Roux Abhik Roychoudhury Ernst Ruediger Olderog Theo Ruys Ugo de Ruys Claudio Sacerdoti Coen Davide Sangiorgi Zdenek Sawa Karsten Schmidt Alan Schmitt Philippe Schnoebelen Carsten Schuermann Thomas Schwentick Stefan Schwoon Christof Simons Riccardo Sisto Pawel Sobocinski Chin Soon Lee Jiri Srba Till Tantau Jan Tertmans Simone Tini Alwen Tiu Mikko Tiusanen IX Irek Ulidowski Yaroslav Usenko Frank Valencia Frank van Breugel Jaco van de Pol Franỗois Vernadat Bjorn Victor Maria Vigliotti Walter Vogler Igor Walukiewicz Pascal Weil Lisa Wells Michael Westergaard Thomas Wilke Tim Willemse Jozef Winkowski Guido Wirtz Lucian Wischik Hongseok Yang Gianluigi Zavattaro Marc Zeitoun TEAM LinG 518 M Viswanathan and R Viswanathan be derived and therefore not included in the syntax of primitive terms Following standard conventions, we write to mean the type and as shorthand for We use a type system to identify a subset of the terms generated by the above grammar as being well-formed Besides restricting the application of functional terms to arguments of the right type, the main purpose of the typing rules is to ensure that in a term the term is monotonic in its variable to assure the existence of the least fixed point The type system consists of proof rules for deriving judgements of the form where the context is a sequence of the form with variables all distinct and each variance annotation A derivable judgement is read as consisting of two assertions: (1) if variables have types respectively then is a well-formed term of type A, and (2) the variance of the term in the variable is given by the annotation if then is monotonic in if then is antimonotonic in and if then nothing about the variance in is asserted In defining the typing rules, we use the following notation For a variance we define its negation as: and This definition is extended pointwise to contexts, so that for a context the context is defined to be The type system is given in Table and consists of axioms for ff, propositional constants, and variables, and inference rules for the remaining term constructs As is to be expected, the proof rule requires the variable to appear monotonically in the body The most interesting typing rule is that for application which splits into three cases depending on the variance of the function being applied in its argument It is most easily understood on the basis of the semantic requirement of derivable typing judgements given by the second part of Lemma below The typing rules are simple but account faithfully for some of the subtleties in the interaction of negation with variables of higher-order type As a simple example, consider the term which at first glance seems to TEAM LinG A Higher Order Modal Fixed Point Logic 519 have appearing negatively Following the typing rules (var) and (not), we can see that appears positively and appears negatively, but the variance in depends on the variance of the variable in its argument type; it would in fact be a positive occurrence if is antimonotonic Indeed, using the typing rules, we can derive from which it follows that is a well-typed term of type — a recursive definition of an antimonotonic function The following proposition states a technically useful property of the type system, where we use to denote syntactic identity Proposition (Unique Types) If and are derivable, then In particular, every closed term has a unique type From Proposition and the form of the typing rules (every construct has a unique rule for its introduction except for application but whose proof rule is uniquely determined by the type of the subterm), it follows that the derivation tree is unique as well (upto renaming of any bound variables) The proof of Proposition is a straightforward induction on the length of the derivation, but it holds only because of the inclusion of the type and variance annotations for bound variables in the syntax of terms For example, without type annotations, the term can be given any type A, and without variance annotations, the term would have both the types and We are now ready to define the semantics of terms Let be a transition system An environment is a possibly partial map on the variable set For a context we say that is written if for We write for the environment that maps to and is the same as on all other variables: if and for some type A then where is a variable that does not appear in For any well-typed term and environment Table defines TEAM LinG 520 M Viswanathan and R Viswanathan its semantics to be an element of Referring to Table 2, in the case of the application term the type is the unique type (as given by Proposition 2) of the term in the context the context is if and is if For a context we define the preorder relation on environments as iff for (the relation as given by Definition 2) We then show by induction on the typing derivation that the semantics of terms given in Table is well-defined as an element of the appropriate type and is monotonic with respect to the preordering on the context Lemma (Semantics of Terms) Let derivable and environments (Well-Definedness): (Variance): If be a transition system For any we have the following: and is uniquely defined then Since for any closed term there is a unique type such that is derivable, we use to denote where the environment is undefined on all variables Formulas are closed terms of type Prop, i.e., terms such that is derivable As is standard, a transition system satisfies a formula, iff the initial state A property of a class of transition systems is simply a subset A property of a class of transition systems is expressible if there is a characteristic formula such that for any we have that iff For a closed term we write for the derivability of 3.1 Invariance Under Bisimilarity Satisfaction of any HFL formula by a transition system is invariant under bisimilarity of transition systems This property cannot be established directly by induction because HFL formulas (closed terms of type Prop) can have subterms of higher-order type — we therefore need to suitably relate the semantics of higher-order terms in different transition systems For transition systems and and states we write to denote that (with respect to is (labelrespecting) bisimilar to (with respect to and iff For any type A, we define a binary relation by induction on the type A as follows (where we use the infix notation to denote that For a context and as iff define the relation for between The TEAM LinG A Higher Order Modal Fixed Point Logic 521 following lemma establishes the connection between the semantics of higherorder terms in different models and is proved by induction on the structure of terms As an immediate corollary, bisimilar transition systems satisfy the same set of HFL formulas Lemma Let be any derivable term For any transition systems and respective environments with we have that Corollary (Bisimilarity Invariance) If iff 3.2 then for any formula Model Checking The model checking problem for HFL is decidable over finite state transition systems This is an immediate consequence of the fact that for any finite transition system the underlying set of is finite for every type B It therefore follows that can be computed inductively on the term (following the definition in Table 2) and using the standard iterative approximations to compute the semantics of fixed point terms These iterative approximations for a fixed point term of type B converge after at most iterations where is the length of the longest strictly increasing chain in the partial order (which is a finite number for any type B) This model-checking procedure is effective but not the most efficient; we leave exploration of other model-checking methods such as those based on tableaux to future work Expressiveness of HFL Section 4.1 describes some basic definable operations in HFL that are used in developing the expressivity results, and Section 4.2 shows that HFL can express the assume-guarantee semantics of [8] In Section 4.3, we show that the fixed point logic with chop (FLC)[1] can be translated into HFL so that any property expressible in FLC can also be expressed in HFL In Section 4.4, we describe a representation of FLC formulas as transition systems over which we can diagonalize to construct properties inexpressible in FLC In Section 4.5, we show that such a diagonalized property can be expressed in HFL, thereby establishing that HFL is strictly more expressive than FLC 4.1 Definable Operations Using standard dualities, we can define terms tt (the set of all states), (set intersection), and each of these terms is of type Prop and require to be of type Prop Greatest fixed points, written can be defined at arbitrary types A and require to be of type A with appearing positively TEAM LinG 522 M Viswanathan and R Viswanathan For any type A, we can define a closed term denoting the least element at the type A Call a transition system finitely strongly connected if it is strongly connected under transitions that have labels belonging to some finite set Over a finitely strongly connected transition system, we can define functions on the type Prop by case-analysis Let be terms of type Prop, and be terms of type for some type A We can define a term of type denoting a function that when applied to a singleton set is a state), returns if and returns if We use as syntactic sugar for the missing else clause returning Note that by its very definition, the case-defined function cannot be monotonic or antimonotonic in its argument (of type Prop) 4.2 Assume Guarantee Properties In this section, we show how assume-guarantee properties can be expressed in HFL The encoding directly follows the informal recursive definition presented in Section 2; the main interest here is illustrating its well-typedness and its type We define the closed term AssGuar as which is typable as AssGuar: This typing judgement can be read as asserting that the assumption property (its first argument) and the guarantee property (its second argument) are required to be monotonic and that the assume-guarantee property itself varies antimonotonically in its assumption and monotonically in its guarantee Constructing the type derivation for AssGuar is instructive in showing how these natural properties of AssGuar follow directly from the constraints imposed by the type system of Table The following proposition shows that the term AssGuar encodes assumeguarantee properties and establishes that HFL is closed under assume-guarantee specifications Proposition (Expressibility of Assume-Guarantee) Consider any transition system with state set S and any monotonic functions Then we have that 4.3 Translating FLC into HFL Let Act, and be as described in Section The following grammar describes the syntax of FLC formulas, where TEAM LinG A Higher Order Modal Fixed Point Logic 523 The formula is the negation of thus, negation in FLC is only applicable to propositional constants Formulas are interpreted in FLC as predicate transformers, i.e., functions that are monotonic with respect to the subset ordering The formula term denotes the identity function, and the chop operator; denotes function composition An environment for a formula is a map from variables to monotonic functions from to that is defined on all the free variables of For such an environment the FLC-semantics of a formula, written, yields a monotonic function from to The reader is referred to [1] for the details of this definition, though it should also be clear from the translation into HFL that we next describe A transition system satisfies a closed FLC formula, written iff i.e., the intial state is in the set obtained by applying the semantics to the full state set S The superscript or subscript refers to the semantics or satisfaction relation in the FLC logic Every FLC formula can be interpreted naturally as an HFL term of type Table details the straightforward inductive translation of any FLC formula into an HFL term it follows almost directly the semantics of FLC defined in [1] The HFL term forms tt, and used in the translation are the definable operations of Section 4.1, and the variable used in the translation of is one that does not appear free in the formula being translated For an FLC formula define the HFL context to be for some enumeration of the free variables of The following theorem shows that the translation is well-typed and preserves the semantics Theorem For any FLC formula following properties: is derivable For any FLC environment for and transition system we have that we have the and As a straightforward corollary, any property of transition systems expressed by an FLC formula can be expressed by the HFL formula tt From the TEAM LinG 524 M Viswanathan and R Viswanathan results established in [1], it then also follows that satisfiability and validity of HFL formulas is undecidable Corollary For any transition system that tt iff 4.4 and closed FLC formula we have Properties Inexpressible in FLC Define the set of subformulas of any FLC formula in the standard way with where is or v Call an FLC formula well-named if each bound variable in the formula is distinct In this case, there is a well-defined function that maps each variable to a unique formula of the form where is or v We identify four action names from the set Act which we call lc, rc, ev, and dm and let A = {lc,rc,ev,dm} These four names can be read as “left child”, “right child”, “evaluation”, and “dummy” We also identify propositional constants from that we will refer to by pterm , and for each We now give our representation of FLC formulas as labelled transition systems Definition For any well-named FLC formula whose action names all belong to the set A = {lc, rc, ev,dm}, the transition system is defined to be where: The labelling function is defined according to the form of the formula: if is one of tt, ff , for some if is of the form term, or for where O is one of and where is or v For any action name The pairs where is of the form for some or where O is one of and is one of v The pairs where is of the form for some and O one of The pairs which satisfy one of the four conditions: (1) is the formula tt, (2) is for some and (3) is for some and (4) is a variable and is Finally, the pairs (where is the formula being represented) and is one of tt, ff, for The transition system from A is finite and strongly connected by the transitions Definition can be intuitively understood as follows The transition system for a formula is essentially its parse tree (with sharing of the trees for common subformulas) with edges directed from child to parent These parse tree edges are labelled with the lc, rc transitions, and the propositional labeling indicates the outermost construct of the corresponding subformula (with standing for TEAM LinG A Higher Order Modal Fixed Point Logic 525 constant literals and for variables) Additionally, we have transitions labeled ev to the constant literals tt,ff , from all the states in which the literals hold (ff does not hold anywhere), and to variables from their defining fixed point formula Note that because the formula is well-named, there is exactly one transition labeled ev to every node Finally, the dummy transition edges dm are added from the root to every leaf node — the only purpose of these edges is to make the transition system strongly connected (thus allowing us to use the case-construct over these transition systems) It also allows us to identify the initial state (as the only one that has a dm transition enabled) By diagonalizing over this representation, we obtain properties of finite transition systems that cannot be expressed in FLC Theorem Let C be any property of finite transition systems such that for any closed well-named formula with actions from A, we have that iff Then C is not expressible in FLC Note that the inexpressible property described by Theorem is unconstrained on transition systems that are not a 4.5 HFL Is More Expressive Than FLC We now show how to construct a formula in HFL that expresses a property of the form prescribed by Theorem Table defines HFL terms whose types are as follows: TEAM LinG 526 M Viswanathan and R Viswanathan with the HFL formula flc-diag expressing a property of the form prescribed by Theorem The properties of the terms decode and init defined in Table are given by the following theorem: Theorem Let be a closed well-named FLC formula over the action set A Consider any subformula For any function for every free in and FLC environment such that The heart of the construction is decode that shows how to decode (in HFL) the transition system representing an FLC formula Its definition given in Table is easiest understood on the basis of its property given in Theorem 3, with the variable read as standing for the function representing an environment and the variable in each of the cases read as standing for the singleton set On an argument the formula is decoded in cases according to its outermost form which in turn is inferred based on which of the propositional constants holds in (standing for For all constructs other than variables and fixed points, their corresponding cases can be understood by close analogy with the HFL-translation of these constructs given in Table together with the understanding that and yield singleton sets including the corresponding subformulas of and that for constant literals term yields the set of states in which the literal holds If is a variable, we evaluate the environment on the set (as given by the property of which is yielded by the term If is a fixed point formula, we correspondingly bind (using or v) a new variable and decode the subformula of (given by but in an environment that is obtained by modifying the current environment to map (given by to (the case-term used for the environment argument to in the fixed point cases yields this updated environment) This ensures that when decoding the subformulas of any use of a variable corresponding to this recursive definition will be decoded as The decoding of the fixed-point cases explains the presence of the environment argument in defining decode Finally, it is worth noting that: (1) decode is a recursive definition of a higher-order function, and (2) because decode is defined by case-analysis, it is not monotonic in the argument (standing for the formula being decoded) These features of HFL are therefore crucial to its definition As an easy corollary of Theorem 3, we get the relevant properties of the terms flc-sem and flc-diag Corollary For any closed well-named FLC formula we have that over the action set A, TEAM LinG A Higher Order Modal Fixed Point Logic 527 iff Combined with Theorem this gives us that the HFL formula flc-diag is a characteristic formula for a property of finite transition systems that is inexpressible in FLC, and thus HFL is strictly more expressive than FLC even over finite transition systems References Müller-Olm, M.: A Modal Fixpoint Logic with Chop In: Proceedings of the Symposium on the Theoretical Aspects of Computer Science Volume 1563 of Lecture Notes in Computer Science., Springer (1999) 510–520 Pnueli A.: In transition from global to modular temporal reasoning about programs In: Logics and Models of Concurrent Systems NATO ASI Series SpringerVerlag (1984) 123–144 Misra, J., Chandy, K.M.: Proofs of network processes IEEE Transactions on Software Engineering SE-7 (1981) 417–426 Abadi, M., Lamport, L.: Composing specifications ACM Transactions on Programming Languages and Systems 15 (1993) 73–132 Abadi, M., Lamport, L.: Conjoining specifications ACM Transactions on Programming Languages and Systems 17 (1995) 507–534 McMillan, K.: Circular compositional reasoning about liveness In Pierre, L., Kropf, T., eds.: CHARME 99: Correct Hardware Design and Verification Volume 1703 of Lecture Notes in Computer Science., Springer-Verlag (1999) 342-345 Henzinger, T.A., Qadeer, S., Rajamani, S.K., Tasiran, S.: An assume-guarantee rule for checking simulation In: Gopalakrishnan, G., and Windley, P., eds: FMCAD 98: Formal Methods in Computer-aided Design, Volume 1522 of Lecture Notes in Computer Science., Springer-Verlag (1998) 421–432 Viswanathan, M., Viswanathan, R.: Foundations of Circular Compositional Reasoning In: Proceedings of the International Colloquim on Automata, Languages and Programming Lecture Notes in Computer Science, Springer (2001) Theoretical Computer Science, Kozen, D.: Results on the propositional 27 (1983) 333–354 10 Stirling, C.: Modal and Temporal Logics In Handbook of Logic in Computer Science Volume Claredon Press, Oxford, UK (1992) 477–563 and 11 Emerson, E.A., Jutla, C.S., Sistla, A.P.: On model checking for the its fragments Theoretical Computer Science 258 (2001) 491–522 12 Lange, M., Stirling, C.: Model Checking Fixed Point Logic with Chop In: Proceedings of the Foundations of Software Science and Computation Structures Volume 2303 of Lecture Notes in Computer Science., Springer (2002) 250–263 13 Lange, M.: Local model checking games for fixed point logic with chop In: Proceedings of the Conference on Concurrency Theory, CONCUR’02 Volume 2421 of Lecture Notes in Computer Science., Springer (2002) 240–254 14 Hopcroft, J.E., Ullman, J.D.: Introduction to Automata Theory, Languages and Computation Addison-Wesley (1979) 15 Burkart, O Caucal, D., Moller, F., Steffen, B.: Verification on Infinite Structures In: Handbook of Process Algebra Elsevier Science Publishers (2001) 545–623 TEAM LinG 528 M Viswanathan and R Viswanathan 16 Hirshfeld, Y., Jerrum, M., Moller, F.: A polynomial algorithm for deciding bisimilarity of normed context-free processes Theoretical Computer Science 15 (1996) 143–159 17 Sénizergues, G.: Decidability of bisimulation equivalence for equations graphs of finite out-degree In: Proceedings of the IEEE Sysmposium on the Foundations of Computer Science (1998) 120–129 18 Tarski, A.: A lattice-theoretical fixpoint theorem and its applications Pacific Journal of Mathematics (1955) 285–309 TEAM LinG Author Index Abdulla, Parosh Aziz 35 Amadio, Roberto M 68 Andrews, Tony Baldan, Paolo 83 Baudru, Nicolas 99 Berger, Martin 115 131 Bollig, Benedikt 146 Borgström, Johannes 161 Bozga, Liana 177 Brázdil, Tomáš 193 Briais, Sébastien 161 Brookes, Stephen 16 Bruns, Glenn 209 Bugliesi, Michele 225 Caires, Ls 240 Cỵrstea, Corina 258 Clarke, Edmund 276 Colazzo, Dario 225 Corradini, Andrea 83 Crafa, Silvia 225 Dal Zilio, Silvano 68 Danos, Vincent 292 Ene, Cristian 177 Gay, Simon 497 Groote, Jan Friso 308 Hirschkoff, Daniel 325 Jagadeesan, Radha 209 Jeffrey, Alan 209 Jonsson, Bengt 35 König, Barbara 83 340 355 Krivine, Jean 292 193, 371 Lakhnech, Yassine 177 Laroussinie, F 387 Leroux, Jérôme 402 Leucker, Martin 146 Lozes, Étienne 240 Ma, Qin 417 Maranget, Luc 417 Markey, Nicolas 387, 432 Melliès, Paul-André 448 Mokrushin, Leonid 340 Morin, Rémi 99 Nestmann, Uwe 161 Nilsson, Marcus 35 O’Hearn, Peter W Pattinson, Dirk Qadeer, Shaz 49 258 Rajamani, Sriram K Raskin, Jean-Franỗois 432 Ravara, Antúnio 497 355 Rehof, Jakob Riely, James 209 Saksena, Mayank 35 Schnoebelen, Philippe 371, 387 193 355 Sutre, Grégoire 402 Tabuada, Paulo 466 Talupur, Muralidhar 276 Thiagarajan, P.S 340 Touili, Tayssir 276 Varacca, Daniele 481 Vasconcelos, Vasco 497 Veith, Helmut 276 Viswanathan, Mahesh 512 Viswanathan, Ramesh 512 Völzer, Hagen 481 Walukiewicz, Igor 131 Willemse, Tim 308 Winskel, Glynn 481 Xie, Yichen Yi, Wang 340 TEAM LinG This page intentionally left blank TEAM LinG This page intentionally left blank TEAM LinG This page intentionally left blank TEAM LinG ... of the 15th International Conference on Concurrency Theory (CONCUR 2004) held in the Royal Society, London, UK, from the 31st August to the 3rd September, 2004 The purpose of the CONCUR conferences... Philippa Gardner Nobuko Yoshida (Eds.) CONCUR 2004 – Concurrency Theory 15th International Conference London, UK, August 31 – September 3, 2004 Proceedings Springer TEAM LinG eBook ISBN: Print... shared-variable concurrency Unpublished manuscript, January 2002 TEAM LinG 34 S Brookes 12 P.W O’Hearn Resources, Concurrency, and Local Reasoning This volume, Springer LNCS, CONCUR 2004, London, August 2004