ETAPS 2004 was the seventh instance of the European Joint Conferences on Theory and Practice of Software. ETAPS is an annual federated conference that was established in 1998 by combining a number of existing and new conferences. This year it comprised ?ve conferences (FOSSACS, FASE, ESOP, CC, TACAS), 23 satellite workshops, 1 tutorial, and 7 invited lectures (not including those that are speci?c to the satellite events). The events that comprise ETAPS address various aspects of the system - velopment process, including speci?cation, design, implementation, analysis and improvement. The languages, methodologies and tools that support these - tivities are all well within its scope. Di?erent blends of theory and practice are represented, with an inclination towards theory with a practical motivation on the one hand and soundly based practice on the other. Many of the issues inv- ved in software design apply to systems in general, including hardware systems, and the emphasis on software is not intended to be exclusive.

Inhalt
Invited Contributions.- Intruder Theories (Ongoing Work).- Theories for the Global Ubiquitous Computer.- Contributed Papers.- Choice in Dynamic Linking.- Soft lambda-Calculus: A Language for Polynomial Time Computation.- On the Existence of an Effective and Complete Inference System for Cryptographic Protocols.- Hypergraphs and Degrees of Parallelism: A Completeness Result.- Behavioral and Spatial Observations in a Logic for the ?-Calculus.- Election and Local Computations on Edges.- Decidability of Freshness, Undecidability of Revelation.- LTL over Integer Periodicity Constraints.- Unifying Recursive and Co-recursive Definitions in Sheaf Categories.- Deriving Bisimulation Congruences in the DPO Approach to Graph Rewriting.- A Denotational Account of Untyped Normalization by Evaluation.- On Finite Alphabets and Infinite Bases: From Ready Pairs to Possible Worlds.- Specifying and Verifying Partial Order Properties Using Template MSCs.- Angelic Semantics of Fine-Grained Concurrency.- On the Expressiveness of Infinite Behavior and Name Scoping in Process Calculi.- safeDpi: A Language for Controlling Mobile Code.- Distance Desert Automata and the Star Height One Problem.- Adhesive Categories.- A Game Semantics of Local Names and Good Variables.- Partial Correctness Assertions Provable in Dynamic Logics.- Polynomials for Proving Termination of Context-Sensitive Rewriting.- Bisimulation on Speed: Lower Time Bounds.- On Recognizable Timed Languages.- Tree Transducers and Tree Compressions.- On Term Rewriting Systems Having a Rational Derivation.- Duality for Labelled Markov Processes.- Electoral Systems in Ambient Calculi.- Strong Normalization of -Calculus with Explicit Substitutions.- Canonical Models for Computational Effects.- Reasoning about Dynamic Policies.-Probabilistic Bisimulation and Equivalence for Security Analysis of Network Protocols.- Strong Bisimulation for the Explicit Fusion Calculus.- Perfect-Information Stochastic Parity Games.- A Note on the Perfect Encryption Assumption in a Process Calculus.