This volume documents the progress of application and theory of Petri Nets since the Advanced Course on General Net Theory of Processes and Systems, held in Hamburg, October 8-19, 1979, This course presen ted in detail wha t had been achieved in this area since the first studies of concurrent systems 20 years ago, After this course it seemed worthwhile to establish a co-operation between different groups working in the field of Petri N ets, The starting points were the AFCET Special Interest Group "Systemes Paralleles et Distribues" and the Gl Special Interest Group "Petrinetze und verwandte Systemmodelle", Meanwhile, group s of many European countries are involved, A main activity of this co-operation is the realization of workshops in varying European countries, The first workshop of this kind was carried out in Strasbourg (France), September 23-26, 1980, The second one took place in Bad Honnef (Germany) September 28-30, 1981. This volume contains contributions of these two workshops, The 1980 workshop in Strasbourg was partitioned into 6 topics : (1) Application of Nets to Realtime Systems, (2) Programming Languages and Software Engineering, (3) Information Flow and Concurrency, (4) Net Morphisms and High Level Petri Nets, (5) Mathematical Analysis and N et Languages, (6) Reliability and Recovery Issues, In this volume, the chairman of each topic gives a short introduction to his area whict should help to understand its specific problems and to in troduce the presented papers,

Inhalt
One: First European Workshop On Application And Theory Of Petri Nets - Strasbourg -.- Application of Nets to Real-Time Systems.- Overview.- Petri Net Modelling and Reliability of Distributed Algorithms.- Using Petri Nets in Measurements of a Distributed Data Base System.- On the Problem of Time in Nets.- Programming Languages and Software Engineering.- Overview.- Transforming Nets Along the Syntactic Production of Programs.- Design-Review by Petri-Nets.- Concurrency in Functional Descriptions.- RNL - A Language for Digital Systems Design Based on Nets.- Galileo: A Methodology for Modelling and Designing Real Time Systems.- Petri Nets and Semantics of System Descriptions.- Information Flow and Concurrency.- Overview.- The Relationship Between Time and Information.- Information Flow in Nets.- An Exercise in Processes with Infinite Pasts.- Two Alternative Definitions of Synchronic Distance.- On the Construction of System Nets.- Net Morphisms and Higher Level Net Interpretations.- Overview.- Net Morphisms and Software Engineering.- An Equivalence-Notion for Condition/Event - Systems.- Recursive Nets.- Behaviour of a Place - Transition Net on a Subset of Transitions.- Stepwise Refinements of Transitions and Places.- Transfer of graph constructs in Goguen's paper to net constructs.- Structural modifications in Net Theory.- Mathematical Analysis and Net Languages.- Overview.- Iterative Methods for the Analysis of Petri Nets.- Inductive Assertions for Analyzing Reachability Sets.- Leakage Notion.- Graph-Theoretical Analysis of a Subclass of Petri Nets.- Synthesis of Concurrent Systems.- Subclasses of Self-Modifying Nets.- Test On Zero in Petri Nets.- Deterministic Languages of Petri Nets.- A Study of the Projection Operation.- Reliability and Recovery Issues.- Overview.-Petri-Net Implementation of Recovery Strategies in a large ESS.- Petri Nets and Reliable Real Time Systems.- Towards Fault Tolerant Real Time Systems by Using Petri Nets.- Treatment of Recovery Problems Using Cuts in Occurence Nets.- Two: Second European Workshop on Application and Theory of Petri Nets - Bad Honnef -.- Use of the Behaviour Equivalence in Place-Transition Net Analysis.- Modeling and Proofs of a Data Transfer Protocol by Predicate/ Transition Nets.- On the Logic of Concurrency and Conflict.- Superposed Automata Nets.- Evaluation Based upon Stochastic Petri Nets of the Maximum Throughput of a Full Duplex Protocol.- Weighted Synchronic Distances.- A Simple and Fast Algorithm to Obtain All Invariants of a Generalized Petri Net.- Constructive Proofs as Programs Executable by PrT Nets.- Correctness Proof for the Alternating Bit Protocol by Assertion Systems.- A Fair Competition Between Two or More Partners.